'm^^ y -*?'^- v(:\\" PE AOTICAL ANT» *'Tr, OliETTCAL A E I T H M E T I C , IX ADBITION TO TUS USUAL ilOPP^ OF ^ PKRATTON, THE SCI- OF NUMBEllS, THE PKCh', 'x SYSTEM, AND OTHER TilTOi: ?, HCLP A p:; BY HORATIO N. ROBiNSOxV, A M., AUTHOR OF V C;)l;u-[; Of >rATHE:M.>.av::3. JOUS COLLEGES, AXD PKIYATJl STUDFXTS. JACOB [N STREET. RY Y Of I NIA I f i?SITY Of LIK>RH1A «X(HIUnB. ^^ • • • d?>:p ROBINSON'S MATHEMATICAL, PHILOSOPHICAL, AND ASTRONOMICAL CLASS BOOKS, PUBLISHED AND FOR SALE BY JACOB EHNST, lis JUalBi street, €iBiciEBii:^ti. FOR SALE IN boston: B. B. VU6SET ft CO. ; E. DAVIS !c CO. ; W. J. REYNOLDS b CO. ; PHILIJPS. SAMPSON b CO. NEW YORK: MASON BROTHERS ; D. BURGESS & CO. ; NEWMAN & IVISON ; PRATT, VTOODFORD ft CO ; A. S. BARNES ft CO. PHILADELPHIA! UPPINCOTT, QRAMBO ft CO.; THOMAS, COWPERTHVTAITE ft CO.; E. H. BUTLER k CO.; URIAH HUNT & SON. BUFFALO, N. Y. FHINNET & CO. ; DERBY, ORTON & MULUGAH. SYRACUSE, N. Y. E. U. BAECOCK k CO. AND THE PRINCIPAL BOOKSELLERS IN THE UNITED STATES. A A NEW PKACTICAL AND TIIEOllETIC AL ARITHMETIC, ^ IN WHICH, IN ADDITION TO THE USUAL MODES OF OPERATION, THE SCIENCE OF NUMBERS, THE PRUSSIAN CANCELING SYSTEM, AND OTHER IMPORTANT ABBREVIATIONS, HOLD A PROMINENT PLACE. BY HORATIO N. ROBINSON, A. M. AUTHOR OF A COURSE OF MATHP:mATICS. DESIGNED FOR SCHOOLS, COLLEGES, AND PRIVATE STUDENTS. \ JOHM S. PV^ELL Civil ( . ^Ineer, 8AN FRANCl^Cg, GaL CINCINNATI* JACOB ERNST, 112 MAIN STREET 1854. woaaia ua. Entered according to Act of Congress, in the year 1845, BY E. MORGAN & CO., In the Clerk's olfice for the District Court of Ohio. ^U^Ck 1 Stereotyped by J. A. Jamee, Cincinnati. h ED'JC. UBRARY Civil & Mechanical Engineer. SAN FRANCISCO, CAL. PREFACE. The public may very properly inquire, what is. 15016 dollars. 11. A certain regiment of soldiers consists of eight companies, and each company consists of 80 men ; how many soldiers are there in the regiment? Ans. 640. 12. How many men are there in an army consisting of 52714 in- fantry, 5110 cavalry, 6250 dragoons, 3927 light horse, 928 artillery, 250 sappers, and 406 miners ? Ans. 69585. 13. A merchant deposited 56 dollars in a bank on Monday, 74 on Tuesday, 120 on Wednesday, 96 on Thursday, 170 on Friday, and 50 on Saturday ; how much did he deposit during the week ] Arts. 466 dollars. 1 4. A merchant bought at public sale 746 yards of broadcloth, 050 yards of muslin, 2100 yards of flannel, and 250 yards of silk ; how many yards in all ? Ans. 3746 yards. FEDERAL MONEY. (Art. 8.) This is the name given to the established currency of the United States ; and it is purposely adjusted to run on the same scale of computation as abstract numbers : that is, fen of one order making one of the next superior order. Therefore, this money must be added by the same rule as whole or abstract numbers. Its denominations are Eagles, Dollars, Dimes, CeJits, and Mills.* Eagles are the highest, and mills the lowest. Ten mills make a cent, ten cents make a dime, ten dimes make a dollar, and ten dollars make an eagle. In practice, mills, dimes, and eagles are disregarded *The coins of the United States are eagles, half-eagles, and quarter-eagles, of gold ; the doUnr, hall'-dollar. quarter-dollar, dime, an half-dime, of silver ; the cent and halt'-cent of copper. 20 ARITHMETIC. in naming money, and we have dollars and cents only. The eagles are read ^s dollars, the dimes as cents; and the mills are quite ne- glected in aggregate sums. The dollar is considered as unity ; its mark is $, and a point., called i\\e decimal point, is placed at the right hand of the dollars to separate them from the inferior denominations. 'J''hus, twelve dollars and seventy-five cents is written, $12.75. In reading, if all the denomination? were named, we should say one eagle, two dollars, seven dimes, and five cents; but this would he too formal and ijiconvenient. We may change the unit by removing the deci- mal point; thus, in the above sum, twelve dollars and seventy-five cents may be considered 1275 cents, the point only is removed, and a cent is now unity in place of a dollar. The following rule for addition in federal money corresponds to the dollar being unity : d stands over dimes, c over cents, and m over mills; but in practice these are not written, for the localily from the decimal point determines the value and denomination of the figure. RuLK. rhtce dollars under dollars, cents under cents, SfC, and add as in whole numbers ,- and put the separatrix in the sum to- taL under the separating points above. If the cents are less than 10, a cypher must be put in the place of dimes. (0 (2) (3) (4) $ d c m $ d c d m $ d c m 139.8 6 7 4319.8 9 .9 7 6 81.0 5 3 1273.5 9 4 3287.8 .4 5 8 67.4 I 2 9807.(i 1829.1 6 .6 2 9 37.4 5 3 7695.2 4 130.0 1 .5 8 3 21.6 5 3 $18916.3 1 207.5 7 1 5. What is the sum of 140 dollars 9 cents, 24 dollars 16 cents, 5 dollars 25 cents, 5 dollars 5 cents, and 304 dollars 8 cents and 9 mills. Ans. $478,639. 6. A man left his estate to his two children, who, after payment of the debts, amounting to 645 dollars 75 cents, received each 3842 dol- lars ; how much was the whole estate ? Ans. $8329.75. 7. If I owe to A 50 dollars and 8 cents, to B 12 dollars more than that sum, and to C 75 cents more than to both the other.s, how much do I owe them all ? Ans. $265.07. 8. A farmer purchased a cow for $14.75, a horse for $75.14, a wag- on for $31,375, and a harness for $41,625; what was the whole amount? ^/7.s. $161.89. 9. My grocer sends me the following bill : To 2 pounds of coflfee at 12 cents 5 mills per pound; a roll of butter for 87| cents; and a box of soap for 2 dollars and 65 cents; what is the amount of the bill ? Ans. $3,775. 10. What is the sum of 25 eagles, 62 dollars, 8 dimes, 75 cents, and 5 mills, properly expressed in dollars and cents ? Ans. $313.55^. ADDITION. • 21 Quesf/oris. How many primary rules of arithmetic are there? W'liat are they called ? What is addition ? How do you place nunihers to be added? Whore do you begin the addition? Why do you carry one for ten, in preference to any other number ? W'hy, at the last column, do you write the whole number? Why is federal money added as natural or abstract numbers ? SUBTRACTION. (AnT. 9.) "SiMPLK SuKTnACTiON is taking a less number from a greater, and noting the difference or remainder; thus, 6 taken from 10, theditierence is 4; and 5 dollars taken from 7 dollars, leaves a re- mainder of 2 dollars. By signs, these examples may be expressed thus: 10—6=4; 7—5=2. " The larger of the two numbers is called the minuend, the lesser is called the subtrahend, and the difference is called their remainder.''^ JIEiXTAL EXEnciSES. 1. Charles had 25 cents, and paid 10 of them for a book ; how many had he left ? 2. A merchant, 35 years old, had been in trade 13 years ; at what age did he commence business 1 3. A father who was 37 years of age, had a son 25 years younger; how old was the boy ? 4. A horse and harness cost 183 dollars. The harness cost 84 dollars ; what was the price of the horse 1 5. Dr. Franklin died in 1790, at the age of 84 ; in what year was he born ? 6. A man paid 84 dollars for a watch, but was obliged to sell it for 07 dollars ; how many dollars did he lose] NoTK. — All operations in both addition and sublraction g^o back to the mental proce.ts ; hut when results are written down as last as they are at- tained, it is called written arithmetic. And the art of writing comes in to help ihe mental process, and enables the mind to concentrate its powers on a sing^le point at atime. liCt ns write the last problem, and submit it to a more artificial process; but when written, if we consider only one figure at a time, we cannot sub- tract 7 from 4. We must, therefore, decompose (he numbers, thus : 84=70-1-14 67=60-f- 7 Difference, I0-|- 7, or 17. Again, let us subtract 765 from 1234. To analyze this, 1234 must be so 22 ARITHMETIC. separated tliat it would be possible to subtract 7 liundreds, 6 tens, and 5 uuils from it, thus: 1234=1100-1-1204-14 765= 700-}- 60-f- 5 Dlff rence, 4tj9= 400-|- GO-j- 9 "\Vc decompose the numbers to enable the pupil to perceive the raiionale of llie vviiole operation. Thus, it will be observed that we must take 5 uiiiis from 14 uiii:s; but, to make the 4, 14. we must, (as it is called), borrow a ten, or one iVom the tens. Then it will be G I'rom 2. or 12, (but in place of 6 from 12. we mav say 7 from 13. the difference is the same). Tlien, 7 fioiri 11, or wiiicli gives the same difference, 8 I>om 12. 4. Hence, when we subtract a figure irom a less one above, we conceive tlie upper figure increased by 10, and the next figure in the lower line increased by one to compensate it. From these observations we draw the following liuLK, To operate on large numbers, set doivn the less niunher under the greater, units under units, tens under tens, S(C., and draw a line htntath them. Then, beginning at the right hand, subtract each figure from the one directly over it, and set down the remainder. Bat if the upper figure be the least, suppose it to be increased bij ten ; then make the subtraction, set down the rernainder, and carry one to the next figure of the subtrahend. Pkoof. Add the remainder to the subtrahend. If their sum is equal to the minuend, the work may be regarded as right. EXAMPLES. Minuends, Subtrahends, Remainders, Proofs, 859267 107895 751372 859267 (4) 10000 4 (5) 3000 999 (2) 6794213 975678 5818535 6794213 (6) 6798 4000 (3) 19067803 04202196 148G5607 19067803 (7) (8) 10000 87000 1 1009 Remainders, 9996 2001 2798 9999 85991 9. Ft 10. From 11. — 12. — 13. — 14. — 15. — 16. — 17. — 78213609 take 27821890. Ans. 50391719. 196 487 875 967 1001 9765 87696 455692 take 37. 96. 302. 351. 487. 1307. 10091. 300120. Resul 159 391 573 616 514 8'158 77605 155572 SUBTRACTION. 23 18. From eleven thousand and eleven Ijumlred take. 1521). liciii. 10580. 19. From thirty thousand and ninely-scvi-n, take one thousand six hundred and lilty-four. Ktm. 2841:3. 20. From one hundred million two hundred and lorty-.seven thou- sand, take one million four hundred and nine. Kern. 9924G591. 21. Subtract one from one million. Rem. 999999. APPLICATION. 1. Sir Isaac Newton was born in the year 1642, and died in 1727 ; to what age did he live? Ana. 85 years. 2. A merchant gave his note for 5200 dollars. He paid at one time 2500 dollars, at another time 175 dollars ; what remained due ? Ans: 2525 dollars, 3. -In 1800 there were 903 post-offices in the United States, and in 1828 there were 7530 ; how much had their number increased ? Aus. 6627. 4. A farmer owned 360 acres of land, and sold 175 acres; how- many acres had he left! ^1"^. 185. 5. Massachusetts contains 7800 square miles, and New Hampshire 9491 square miles; which is the largest, and by how many square miles ? 6. New York contains 46085 square miles ; how much larger is it than Massachusetts ? than New Hampshire ? than both these States together ] 7. The Declaration of Independence was published July 4th, 1776 ; how many years to July 4th, 1850? 8. Gunpowder was invented in the year 1330 after Christ, and the art of printing in the year 1441 ; how long from each of those events to the year 1850? 9. The mariner's compass was invented in Europe in the year 1302 ; how long since that event to the present year ? 10. A man deposited in bank 8752 dollars, and drew out at one time 4234 dollars, at another 1700 dollars, at another 962 dollars, and at another 49 dollars ; how much had he remaining in bank 1 Ans. 1807 dollars. 11. A merchant bought 5875 bushels of wheat, and sold 2976 bushels', how many bushels remain in his possession ? Ans. 1899 bushels. 12. A grocer bought 25 hogsheads of sugar, containing 250 hun- dred weight, and sold 9 hogsheads, containing 75 hundred weight; how many hogsheads and how many hundred weight had he left. Ans. 16 hogsheads and 175 hundred weight. 13. A traveler who was 1300 miles from home, traveled homeward 235 miles in one week, in the next 275 miles, in the next 325 miles, and in the next 280 miles; how far had he still to go before he would reach home? Ans. 175 miles. 24 ARITHMETIC. SUBTRACTION OF FEDERAL MONEY. (Art. 10.) Rule. Place dollars under dollars, cents under cents, Ac- ; proceed as in whole numbers, and put the separatrix in the remainder, under the decimal points above. (I) (2) (3) $ c $cm $cm From 75.48 246 05 6 6327.86 5 Take 58.76 218.60 7 4961. Ans. §16.72 (2) $ c m 246 05 6 218.60 7 4. From 36 dollars and 5 cents, take 28 dollars and 60 cents. Rem. $7A5. 5. From two dollars, take 5 dimes and 5 mills. Rem. §1.49^. 6. From 2 dollars, take 7 cents. Rem. $1.93. 7. From 4 dollars, take 75 cents. Rerii. $3.25. 8. Owing my neighbor 60 dollars, I paid him at one time §9.50 ; at another 5il5; at another $30.75; and at another 62^ cents ; how much was then due him? Ans. §4.12^. 9. A man paid for two sheep 7 dollars and 50 cents, and for a cow twice as much, lacking 75 cents; how much did she cost him ? An>: $14.25. 10. A farmer's bill at a store amounted to $37,625, and he paid $19 and 5 cents in oats ; how much did he still owe ? Ans. $18,575. 1 1. A man owes §100 : he has §47.375 ; how much must he bor- row to pay the debt? Ans. §52.625. 12. A man sold his house and lot for §2070, which was §62.875 more than it cost him ; what did it cost him ] Ans. §2007.125. Questioiis. What is subtraction? What is the greater number called ? What is the less number called 1 What is the difference called ? How do you place numbers for subtraction? When the lower figure is greater than the upper one, how do you proceed ? Why is the 07ie you borrow, one ten ? Ans. Because ten ones make one ten ; and if I borrow one ten, it will make ten ones again, &c. How do you prove subtraction ? MULTIPLICATION. (Art. 11.) Multiplication is the repetition of the same num- ber, hence, it can be performed by addition. MULTIPLICATION. 25 Tlie number to be repeated is called the multipHcancf, the number of times it is to be repeated is called the multiplier, and the result is called the product. 'I'he multiplier and multiplicand are also called factors of the product. EXAMPLE. Let 8 be repeated three times, thus: 8-}-8-f-8=24. The short mental operation of saying and comprehending tiiat 3 times 8 are 24, is called multiplication ; 8 is called the multiplicand, 3 the multiplier, and 24 the product. But this is arbitrary : we may call 3 the multi- plicand, and 8 the multiplier ; and it will then be required to repeat 3, 8 times : hence, in point of fact, it is indifferent which of the two factors is called the multiplier, and which the multiplicand. Any two or more numbers which, multiplied together, produce a third number, are cMed factors of the number. A number may have many different factors ; for example, 36 may have for factors 3 and 12, 2 and 18, 4 and 9, 6 and 6, or 2, 3 and 6, because — 3X12=36 2X18=36 4X 9=36 6X 6=36 2X3X 6=36. MULTIPLICATION TABLE. 2X 1= 2 iX 1= 4 6X 1= 6 SX 1 = 8 lOX 1= 10 2X 2= 4 4X 2= 8 6X 2=12 8X 2= 16 lOX 2= 20 2X 3= 6 iX 3=12 6X 3=18 8X 3= 24 10 X 3= 30 2X 4= 8 4X 4=16 6X 4=24 8X 4= 32 lOX 4= 40 2X 5=10 IX 5=20 6X 5=30 SX 5= 40 lOX 5= 50 2X 6=12 iX 6=24 6X 6=36 8X 6= 48 lOX 6= 60 2X 7=14 4X 7=28 6X 7=42 SX 7= 56 lOX 7= 70 2X 8=16 4X 8=32 GX 8=48 8X 8= 64 lOX 8= 80 2X 9=18 IX 9=36 .^X 9=54- SX 9= 72 10 X 9= 90 2X10=20 4X10=40 0X10=60 8X10= 80 10X10=100 2X11=22 4X11—11 SX 11=66 8X11= 88 10X11 = 110 2X12=24 4X12=48 6X12=72 8X12= 96 10X12=120 3X 1= 3 5X 1= 5 7X 1= 7 9X 1= 9 IIX 1= 11 3X 2= 6 5X 2=10 7X 2=14 9X 2= 18 11 X 2= 22 3X 3= 9 5X 3=15 7X 3=21 9X 3= 27 I IX 3= 33 3X 4=12 5X 4=20 7X 4=28 9X 4= 36 11 X 4= 44 3X 5=15 3X 5=25 7X 5=35 9X 5= 45 1 1 X 5= 55 3X 6=18 5X 6=30 7X 6=42 9X 6= 54 IIX 6= 66 3X 7=21 ox 7=35 7X 7=49 9X 7= 63 11 X 7= /7 3X 8=24 5x 8=40 7X 8=56 9X 8= 72 11 X 8= 88 3X 9=27 5x 9=45 7X 9=63 9X 9= 81 IIX 9= 99 3X10=30 5X10=50 7X10=70 9X10= 90 11X10=110 3X11=33 5X11=55 7X11=77 9X11 = 99 11X11=121 3X12=36 5X12=60 7X12=84 9X12= 108 11X12=133 26 ARITHMETIC. As multiplication is repeating a sum a given number of times, it is evident that the units, and tens, and hundreds, and every superior or- der of the proposed sum, must be repeated the given number of times ; and in repeating the units, if they amount to any number of tens, and units, the tens must be added into the column of tens, when we re- peat the tens, for the same reason that we carry by tens in addi- tion. To analyze the process, let it be required to multiply 468 by 8 ; that is, repeat 468, 8 times. 468=400-1- 60-|- 8 Repeat each order 8 times, 8 3200-|-480-f64 Or, in a more condensed form, it stands thus Multiplicand, 468 Multiplier, 8 Product, 3744 From this we perceive, that in all cases the tens which arise from repeating the units must be added in w4th the tens that arise from re- peating the tens; and the hundreds which arise from repeating the tens, must be added to the column of hundreds, &c. ; hence, when the multiplier is a single Jigure, we have the following RuLT.. Place ihe multiplier under the units figure of the multi- plicand, and mtiltiply each figure cf the multiplicand in succession, and set down the amount, and carry as in addition, (AuT. 12.) Pnoor. The proof of multiplication is division, for they are reverse operations ; but this method of proof cannot be used until the pupil has learned division. But if we vary the method of multiplying, and find the same result, we may be quite conlident that the result is correct; and some persons would regard it as proof and others would not. For instance, if we have any number, say 231, to be multiplied by 8. We may multiply it by 8 directly, and then for proof, divide 8 into any two parts, say 6 and 2, or 5 and 3, and mul- tiply 231 by 6; then multiply 231 by 2, and the two products added together will be the same as the first result, if no mistakes have been made. Hence, to prove multiplication, we have the following Rult:. Separate the multiplier into any two parts, and multi- ply by such part separately, and add the two results together, and their sum will be the same as by direct multiplication, provided no mistakes have been made. MTLTIPLICATION. 27 EXAMVLES. (1) (2) (3) (4) 3G563 8375 4378 9286 5 6 7 8 182315 50250 ;30G46 74288 APPLICATION-. 1. If I barrel of flour sells for 555 cents, what will 6 barrels come to "^ Ans>. 33:30 cents. 2. If 1 load of hay costs 875 cents, what will 7 loails come to? A?}s. 6125 cents. 3. If 1 cord of wood costs 486 cents, what will 8 cords come to? Ans. 3888 cents. 4. If I yard of broadcloth costs 765 cents, what will 9 yards come to ? Ans. 6885 cents. 5. A lady purchased 54 yards of muslin at 12 cents a yard ; what was the cost of the whole 1 Am: 648 cents. 6. A farmer sold 49 acres of land at U dollars an acre ; what did the whole amount to? Ans. 5.i9 dollnrs. 7. A Carpenter worked ten days at 146 cents a day ; ho.v much did his wages amount to? Ans. 1460 cents. 8. VVliat will 764 pounds of pork come to at 8 cents a pound ? Ans. 61 12 cents, 9. A person spends 9 dollars a week ; how much will he spend in 4G week« ? Ans. 4 14 dollars. 10. If ynu save 12 cents a week, how much will you save in 52 weeks, or 1 year] Ans. 624 cents. 11. James spends for nuts and cakes 8 cents a day ; how much will he spend in a year, or 365 days? Ans. 2920 cents. 12. .lane spends for cakes, nuts, and apples, 6 cer-ts a dav ; how much will she spend in 216 days? Ans. 1296 cents. (Aht. 13.) Before we proceed any further, it is important to re- mark, that multipliers must always be considered as abstract num- bers. Mu!tiplicaii(m is a mere repetition of the Same number, or the same //tin<{;s, a given numl)er of times. 'Vhe number expressing the times anything is to be taken, must be mere count, and cannot repre- sent things. In the first example, if 1 barrel of flour sells for 555 cents, vi'hat will 6 barrels come to? Here the 555 cents cannot be mulfipl'ud by barrels, but it can and must be repeated as many times as there are barrels.* 'i'he same reason applies to all other questions. The quantity which has the same name as the required result is *Tliis maybe considered a nice dislinciion ; hut it is essential, as we find so much carelessness on this poini arnon,£r some of our teachers and in some of our hooks. It is not unfr.-ciuenltlia! we find such demands as the'^e : Mul- 28 ARITHMETIC. always, properly speaking, the multiplicand, whether we practically make it so or not. Thus, in the 12th example: Jane spends for cakes, nuts, and apples, 6 cents a day ; how much will she spend in 216 days ? Here, 6 cents must be taken 216 times, but in practice wc write the operation thus ; 216 6 1296 The largest number is taken for the multiplicand, for it makes no difference : the product of two factors is the same, whichever be re- garded as the multiplicand. When the multiplier consists of more than one figure, the product of the superior figure will be a supeiior product ; for instance, the product of 6 tens, or 60, must be 10 times as much as the pro;luct of 6 ; though we may multiply by any superior figure, in the same manner as we do by the unit figure, only taking care to give the product its true place in the 07'der of numbers. From these consid- erations arises the following Rule. When the multiplier contains more than one JJgure, multiply the multiplicand by each figure of the multiplier, placing the right-hand fig^-ire of each product directly under that figure (f the multiplier Ijy luhic'i it is produced, and take the .sum of all the products. EXAMPLES. 37462 .563 Product of the units, lll^SSo Product of the tens, 224773 Product of the hundreds, 187310 Entire product of 563, tilD9ll06 2. Multiply 4962 . . by . . . 9S Ans. 486276. 3 7331 ..!... 87 642108. 4 4376 97 424472. 5 7923 73 617994. 6 6842 89 608938. 7 7648 523 3999904. P 8473 ..... 456 3S63688, 9 9372 567 5313924. 10 75649 579 43800771. liply 25 cents by 25 cents; multiply 2 shillings and 6 pence by 2 sliiM^ng-? and 6 pence. &c. Now. we can repeal 25 cents, or any other ^^mn of money, as viany times, or an many parts of one time as we pll'a^;o : lun tliere is no such thing as money times money, or imrreis times barrels, or barrels times money. If it were possible to take money times money, what would it produce? MULTIPLICATION. 29 11. .Multiply 29S31 . .by. . 952. . . .^77,^.28399112. 12 252:J8 . . . . 12170 30714G4G0. 13 991)9 6tJ(iO 66593.340. 14 87603 9865 ..... 861203o95. (AuT. 14.) To multiply by 10, we place a cipher at the right; 'i'hus, 5 multiplietl by 10, gives 50; that is, the cipher is put at ihe right of the 5. In the same way, to multiply by 100, we put two ciphers thus— 500; 6 multiplied by 1000, wc have 6000, &c. kxa: IPI.E^-. 10. Multiply 47654 . .by . 10 . . . . . Ans. 476540. 11. ..... 75478 . . 100 . . . . . 7547600 12. 86427 . 1000 . . . . . . 8G427000. 13. 17846 . 10000 . . . . 178160000 14. lOOCO . . . 17S46 . . . . 178160000 It will be observed that examples 13 an.l 14 are tlic same, and pro- duce the sajne results, ft i.s immaterial whether the ciphers are in one factor or the other, or in hotk ; the result will have the same num- ber of ciphers on the right as are contained in both factors. Henct, rvheji ficlors have ciphers on their right, the ciphers may be omit- ted in the operation, and afterwards annexed to the product. Thus : 15. Multiply 47000 by 4200 Operation .• 47 42 9i 188 Kesuit, 197400000 16. MuUiplv 73400 by 72000 Result, 3082SOOOOO. 17 '. 62300 bv 12100 751410000. 18 785400 by 2000 1570800000. When ciphers are between numbers in the multiplier there will be no product corresponding to then), because they signify nothin Divisor 10)1786940 '5) 9)7468542 11)564521705 Quotient 178694 (7) 12)9476521764 (8) 11)546215747 (9) 12)462164684 1 36 ARITHMETIC. The operations may be proved by multiplying the quotients by the divisor, and adding the remainder, if there is any, to the product. If the v»^ork is correct, it will equal the dividend. 10. What will be tlie quotient of 4562, divided by 3 ] Quo. 1520, Rem. 2. 11. What will be the quotient of 44631, divided by 4? Quo. 11157, Teem. 3. 12. What will be the quotient of 62070, divided by 4? Quo. 155)7, Rem. 2. 13. What will be the quotient of 5374, divided by 5 ? Quo. 1074, Rem. 4. 14. What will be the quotient of 7856, divided by 6 1 Quo. 1309, Rem. 2. 15. What will be the quotient of 85362, divided by 7 ? Quo. 12194, Rem. 4:. 16. Divide .... 958 by . 18. . . . Quo. 53 Rem. 4. 17. Divide. . . 1475 by. 28 .52 . . . 19. 18. Divide . . . 4277 by . 31 137 .. . 30. 19. Divide . . . 25757 by . 37 696 .. . 5. 20. Divide. . .63125 by. 123.. • . . . 513 . . . 26. 21. Divide . . 253622 by . 422 601 .. . 22. Divide . . 4049160 by . 328 12345 . . . 23. Divide . 48905952 by 9876 4952 . . . 24. Divide. 25312 by . 226 112 .. . 25. Dividj . . . 43956 by . 666 66 . . . 26. Divid- . 101442075 by 4025 25203. . . 27. Divide' . 367376610 by 158694 2315. . . (Art. 17) As division is the converse of multiplication, and as we niiiltinly by 10, 100, 1000, &c., by annexing the ciphers, (Anx. 14.) thcrctore, when we cut off ciphers, we divide by 10, 100, &c., according to the number of ciphers cut off. But, if there are no ciphers to be cut off. and we wish to divide by 10, 100, 1000, &;c., we may divide by the following RiTLE. Cut off as many figures from the right of the dividend as there are ciphers in the divisor. The figures on the left-hand of the point will be the quotient, and those on the right hand the remainder. r 10 =785.4 . Ans. 785_4_ 7854^^ 100 =78.54 78^_1 1 10 / 1000=7.854 7J_5_4_ ^ 10 Multiplying a number by 10 increases its value tenfold ; and di- viding it by 10 ditninishes it in the same ratio. The former is effect- ed by removing every figure in it one place farther from the unit's place ; the latter, by bringing them one place nearer. When there are ciphers on the right hand of the divisor : DIVISION. 37 Cut off lite ciphers, and an equal number of places from the rii^ht of the dividend: in dividinii;, omit the fih;urcs cut off, and annex' tJicm afterwards to the remainder, if any ; othtrwiac, the fiirin-cs cut off from the dividend are the remainder. Divide 3704196 by 20. Divide 369183 by 7100. (1; (2) 2,0)3704196 7i;00)3r)91|83(51T o.|3 ^,4ns. ' 355 Ana. 18520916 2 141 71 70 3. Divide 2976435 by 2800. 4. Divide 9400639 by 4700. .5. Divide 6749802 by 9000. 6. Divide 4872036 by 1200. Wben the dividend is federal money, the operation is the same as in division of whole numbers, and the only difficulty is to decide the value of the quotient ; but this will be treated more at large when we come to division in decimal fractions. EXAMPLES. !. Divide $375.50 equally among 45 persons. Call the whole sum 37550 cents, and divide by 45. cents, cents. 45)37550(8342 h ■§» <^^'3 i'^ ^^^6 following SUPPLEMENT TO MULTIPLICATION AND DIVISION. (AnT. 18.) To multiply by one-half, is to take the multiplicand one-half of one iime ,- that is, take one half of it, or divitle it by 2. To multiply by j, take a third of the multiplicand, that is, divide it by 3. To multiply by -f , take § first, and multiply that by 2 ; or, multiply by 2 first, and divide the product by 3.-{- EXAMPLES. 1. What will 360 barrels of flour come to, at 5:J- dollars a barrel. At 1 dollar a barrel it would be 360 dollars ; at 5;^ dollars, it would be b\ times as much. *It IS not generally understood that the power of reasoning and the power of coinpaiatiou are separate and distinct faculties; and. to be a good mathe- matician, a person must possess both; but it is most important iliat the rea- soning power should be the most iirominent. Indeed, to become a skillfi.ii mathematician, it is almost necessary that the individual sliould make nu- merical compulations with difficulty ; otherwise, he may not be sufficiently prompted to seek lor fibbreviatiuus and artifices, wiiich, more than anything eisi.'. give beauty and polish to science. t Sometimes one operation is preferable, and sometimes the other ; good judgment alone can decide, when the case is before us. MULTIPLICATION AND DIVISION. 41 360 5 times, . . . 1800 i of a time, . 90 Ans $1890 How much at 5| dollars per barrel ? 360 4)360 5| 90=i of a time. 5 times 1800 3 270 270=1 of 1 time. §2070 2. Forty-eight men were to receive $5| a-piece ; how many dollars were paiiftlieni ? 3. What will 15 tons of hay come to, at $7^ a ton 1 4. A farm of 156 acres was sold for $34f an acre; how much did it come to ? 5. At 16-§ cents a bushel, what will 75 bushels of potatoes cost ? Ans. 1250 cents. 6. What will 27| yards of muslin cost, at 9 cents a yard ? A71S. 249| cents. 7. What will 1| yards of cloth cost at 225 cents per yard ? Aiis. 393^ cents. 8. What is 611 times 35 ? Ans. 242_'_. 9. What is 350 "times 15i ? Ans. 5337^. (Art. 19.) Before we attempt to divide by a mixed number, such as 2^, 3i, 5§, &c., we must explain, or rather observe the principle of division, namely : That, the quofient iviU be the same if we mul- iiplif the dividend and divisor by the same number. Thus, 24 di- vided by 8 gives 3 for a quotient. Now, if we double 24 and 8, or multiply them by any number whatever, and then divide, we shall still have 3 for a quotient. 16)48(3; .32)96(3, &c. Now, suppose we have 22 to be divided by 5^ ; we may double both these numbers, and thus be clear of the fraction, and have the same quotient. 5^)22(4 is the same as 11)44(4. How many times is 1^ contained in 12 ? Ans. Just as many times as 5 is contained in 48. The 5 is 4 times 1|-, and 48 is 4 times 12. From these observations, we draw the following rule for dividing by a mixed number : Rule. Multiply the whole number by the lower term of the fraction ,- add the upper term to the product for a divisor ,- then multiply the dividend by the lower term of the fraction, and then divide. S5 ~" 42 ARITHMETIC. EXAMPLES. 1 . There being 5^ yards in a rod, how many rods in 682 yards ? .5i)682( Double both, 11)1364(124 ^/js. 2. How many barrels of flour, at §5| per barrel, can be bought with $500? Ans. Se^, 3. Thirty-one and a half gallons to the barrel, how many barrels in 485 gallons? Ans. \.5'll, 4. How many times is li contained in 36? A?is. 30 times. N. B. If we multiply both these numbers by 5, they will have the same relation as before, and a quotient is nothing but a relation between two numbers. After multiplication, tlie numbers may be con- sidered as having the denominaiion of fiflhs. 5. How many times is ^ contained in 12? Ans. 48 times. One-fourth, multiplied by 4, gives 1 ; 12, multiplied by 4* gives 48. Now, I in 48 is contained 48 times. 6. Divide 132 by 2|. Ans. 48. 7. Divide 121 by 15-^-. Ans. 8. 8. How many times is ^ contained in 3? Ans. 4 times. ( Art. 20.) Operalions in arithmetic may be considerably short- ened, by a little attention to the relation of numbers. A few exam- ples are adduced of contractions in multiplication. Suppose it were required to multiply a number — say 746382, by 999. (1) Multiply by 1000 (Art. 13.) 746382000 Subtract the multiplicand, 746382 Product 745635618 Here, it is evident that the product of 1000 exceeds the product of 999, by once the multiplicand. 2. Multiply 4532 3. Multiply 4532 bv ... 639 by . . . 963 63=9X7 40788 40788 285516 285516 Product 2895948 Product 4364316 In both the foregoing examples we multiply the product of 9 by 7, because 7 times 9 are equal to 63. MULTIPLICATION AND DIVISION. 43 Because 9 is in the place of hundreds in example 3, the product for the other two figures is stt two places towards the right. In this last example we may commence with the 3 units in the usual way ; then that product hy 2, because 2 times 3 arc 6 ; then the pro- duct of 3 hy 3, which will give the same as the multiplicand by 9. The appearmice of the work, would then be the same as by the usual method, but would be easier, as we actually multiply by smaller numbers. 4. Multiply by. . . . . 40788 497 285516 1993612 20271636 Product of the 7 units. As 7X7=49, multiply the pro- duct of 7 by 7. Observe, that in this last example, 497 is 3 less than 500, and 500 is ^ of 1000. Hence, to obtain the product, we take 40788 one thousand times, which is 40788000, 2)40788000 500 times is 20394000 3 times is 122364 Product, 20271636 5. Multiply 4962, or any other number, by 98 ; that is, take it 98 times. If we take it 100 times, we have 496200 Subtract 2 times 4962, which is 9924 Product, 486276 6. Multiply 299X299X299. Take 299 300 times, and subtract 299, &c. 7. Multiply 999X999X999. Product 26730899. Prod. 997002999. ;Art. 21.) To multiply by 25, take :J- of 100 times, ro multiply by 50, take ^ of 100 times. '- by 75, take | of 100 times. bv 125, take g of 1000 times. by 135, take g of 1000 times-f-10 times. by 150, take 100 times-j-^ of 100 times, &c., &c., for any other aliquot part of 10, 100, or 1000. 44 ARITHMETIC. 8. Multiply 86416 by 135. 125 times is 8)86416000 . 10802000 10 times is 8641G0 Product, . 11666160 9. Multiply any number, say 2636, by 248 2636 248 Commence with the hundreds, . . . Double this for the lens, Double this last for the units, . . . . . . 5272 . . 10544 . . 210S8 Product, . . 653728 Take the same example. Multiply by the units: 3 times 8=24 ; hence 21088 3 Pro 2636 248 21088 63264 63264 duct, 653728 Again, if we add 2 to 248, we h hence, 250 times is ave 250 : 250 is i of 1000; 4)2636000 659000 2 times subtracted 5272 Product, , - - - . . 653728 10. Multiply 87603 by 9865. B. would be a tedious operation ; but, le —135; 135isl25-[-10; 125 is ^ o 876030000 Subt 1182G405 ^ the con t us obs€ f 1000. ract i : 10 tim But 987 imon formal rule, this rve that 9865 is 10000 Therefore, 8)87603000 10950375 eg, 876030 864203595 Product. 11826405 11. Multiply 818327 by 9874. Therefore, 4 is 10000, less 126. MULTIPLICATION AND DIVISION. 45 8183270000 Less ^ of 818327000 Subtract. . J 03 109202 102290S75 8080160798 Product. 818327 103109202 12. Multiply 188 by 135, and that product by 15. Instead of do- ing this literally and mechanically, according to rule, we may half 188 twice, and double each of the factors that end in 5, and we shall have 47 . 270 . . 30; or, 47 8 100 4 70 3 7 6 Product, 3 8 7 U i 13. Multiply anv numl-er, say 468232, by 126"> g 14. by 246 I -^ 15. by 426 ' 16. by 486 17. by 612 18. Multiply 61524 by 273 and by 327. 19. Multiply 342516 by 7209 and by 9072. 20. Multiply 3764 by 199. Take 3764 200 times, and from that product subtract 3764. 21. Muhiply 764 by 498^. Take 764 500 times, and from that product subtract 1^ times 764. 22. Multiply 396 by 21^, or, (which is the same,) 99X87=8700 —86=8613. N. B. Ninety-nine is i of 396, and 87 is 4 times 2 If. 23. A man spends 99 cents a day for 19 years, each year consisting of 365 days ; what is the whole amount 1 We may divide by 5, 25, 50, 125, and other aliquot parts of 10, 100, 1000, &c., in the following manner: How many times is 5 contained in 20 ! Ans. The same number of times as the double of 5, or 10, is contained in the double of 20, or 40. How many times is 50 contained in 762? Ans. The same as 100 in 1524. 46 ARITHMETIC. How many times is 125 contained in 21251 Same as 250 in 4250; Same as 25 in 425 ; Same as 50 in 850; Same as 5 in 85 ; Same as 10 in 170; that is, 17 times. The object of these changes is, to give the learner an accurate and complete knowledge of numbers, and of division ; and the result is not the only object sought for, as many young learners suppose. How many times is 75 contained in 575 ? or, divide 575 by 75. Am. 7^. Divide 800 by 12^ Quotient, 64. Divide 27 by \^ Quo. 1//-, or l^i. A person spent 6 dollars for oranges, at 6^ cents apiece ; how many did he purchase ? Ans. 96. (Art. 22.) When two or more numbers are to be multiplied to- gether, and one or more of them having a cipher on the right, as 24 by 20, we may take the cipher from one number, and annex it to the other, without affecting the product; thus, 24X20, is the same as 240X2; 286X1300=28600X13; and 350X70X40=35X7X4 XIOOO, &c. Every fact of this kind, though extremely simple, will be very use- ful to those who wish to be skillful in operation. (Art. 23.) Before we combine division with multiplication, let us take a more systematic view of numbers. The following are called prime numbers, because no one can be divided by any number less than itself without producing a fraction : 1 2 3.5.7. . .11.13. . . 17 . 19 . . .23 29 31 .... 37 .. .41 . 43 ... 47 53 ... . * 59 . 61 67 . . . 71 . 73 79 . . . 83 . . ... 89 97 . . . 101. The points represent the composite numbers ; and here it can be observed, that there are 27 prime numbers, and. of course, 73 com- posite numbers in the first hundred, the prime numbers becoming fewer as the numbers rise higher. Observe the following series : 5 10 15 20 25 30 35 40 45 60 55 60, and so on. Every body knows that our arithmetical scale of numbers is 1, 10, 100, 1000, &c. Now, we wish the student to observe the numbers, 5 20 25 ^ 50 75 125 500, as being not only in the preceding series, but aliquot parts of some number in our arithmetical scale. For example, 25 is i of 100 ; 125 is i of 1000, &c. We now charge the student to make his eye familiar with all the preceding series — the prime numbers as being unmanageable and in- MULTIPLICATION AND DIVISION. 47 convenient, and the others the very reverse ; hut the full importance of such a study cun only appear in the .sequel. (Art. 24.) When it liecomes necessary to multiply two or more numbers together, and divide hy a third, or i)y a product of a third and fourth, it must he lifenilli/ done, if the numbers are prime. For example: Multiply 19 by 13, and divide that product by 7. 'I'his must be done at full length, because the numbers are prime : and in all such cases there will result a fraction. But, when two or more of the numl)ers are composite numbers, the work can uhcays be contracted. Example : Multiply 375 by 7, and divide that product by 21. To obtain the answer, it is sufficient to divide 375 by 3, which gives 125. 'i he 7 divides the 21, and the foctorS remains for a divisor. Here it becomes necessary to lay down a plan (f operation. Dravy a perpendicular line, and place all numbers that are to be multiplied together under each other, on the right hand side, and all numbers that are divisors under each other, on the left hand side. EXAMPLES. 1. Multiply 140 by 36, and divide that product by 84. We place the numbers thus ; We may cast out equal factors from each side of the line without affecting the result. In this case, 13 will divide 84 and 36; then, the numbers will stand thus: 140 3 But 7 divides 140, and gives 20, which, multiplied by 3, gives 60 for the result. 2. Multiply 4783 by 39, and divide that product by 13. 4783 ^'^ 3 Three times 4783 must be the result. 3. Multiply 80 by 9, that product by 21, and divide the whole by the product of 60X6X14. ^^ 3 ^0 6 2^^ ^0 4 9 # 3 In the above, divide 60 and 80 by 20, and 14 and 21 by 7, and those numbers will stand canceled as above, with 3 and 4, 2 and 3 at their sides. 48 ARITHMETIC. Now, the product 3X6X2, on the divisor side, is equal to 4 limes 9 on the other, and the remaining 3 is the result. Hoping now that the pupil understands our forms, and compre- hends the true philosopliical principles, we give a few unwrought ex- amples for exercises. 4. Multiply 84 by 56, and divide the product by 14 ; what is the result ? 5. What is the result of 75X21, divided by 7 1 6. What is the result of 126X72, divided by 48 1 7. What is the result of 5728X49, divided by 56? 8. What is the result of 64X 18X48, divided by 16X9X13? 9. What is the result of 125X8X2, divided by 100X24 ? 10. What is the result of 39X41X360, divided by 82X30? 1 1. What is the result of 22AX 13X37^, divided by 75X45? 12. What is the result of 71X19X7, divided by 38X211 13. What is the result of 221X635, divided by 35X5 ? APPLICATION. 1. A farmer sold 28 bushels of wheat at 85 cents per bushel, and took his pay in cotton cloth at 14 cents per yard ; how many yards did he receive? -4ns, 170. 2. A person bought 12 yards of cloth at 219 cents per yard, and paid in butter at 9 cents per pound ; how many pounds did it require ? Ans. 292. 3. How many yards of cloth, at $4.66 a yard, must be given for 18 barrels of flour at §9.32 a barrel ? A/is. 36. 4. The children in a Sunday-school contributed 5 dollars to a chari- table object ; each giving 6i cents ; how many children were there ? Ans. 80. 5. A laborer vvrorked 26 days at 87^ cents per day, and look his pay in wheat at 65 cents per bushel ; how many bushels did he re- ceive ? Ans. 35, 6. A person pays 3^ dollars a week for board ; how many dollars must he pay for 26 weeks? Ans. 13 times 7: $91. 7. A merchant bought 526 barrels' of flour at $4 50 per barrel, and paid in cloth at $2.25 per yard ; how many yards did it require ? Ans. 1052. 8. How much land, at §2.50 per acre, must be given in exchange for 360 acres at §3.75 per acre ? An^s. 540. 9. What will 28 pounds of sugar cost, at 9| cents per pound? Ans. 7 times 39 cents : or, §2,75. 10. An auctioneer sold 55 bags of cotton, each containing 400 pounds, receiving 1 mill commission on a pound ; how many dollars did his commission come to ? Ans- §22. 11. How many casks, each containing 1 bushel I peck, are required to hold 145 bushels] Ans. 116. 12. How much will 540 yards of cloth cost at 3 shillings 4 pence per yard, in dollars, at 6 shillings each 1 Ans. §300. MULTIPLICATION AND DIVISION. 49 13. If 1 quart cost 10 pence, how many pounds will IJi hogsheads cost] ybr. £126. 14. How many pounds of butter at 9^ cents per pound, will pay for 19 yards of muslin at II cents per yard ? Aus. 22. 15. How many bushels of oats at 22^ cents a bushel, will pay for 75 pounds of sugar at 5 cents per pound ? An.". 16-f. 16. How many bushels of wheat at 75 cents a bushel, will pay for 6 yards of cloth at 3^ dollars a yard ? Ans. 28. 17. How many bushels of corn at 45 cents per bushel, will pur- chase 24 yards of carpeting at 65 cents per yard ] Ans. 34^. 18. How many tons of hay at 5^ dollars per ton, will pay for 11 acres of land at 19 dollars per acre? Ans. ;38. 19. If a man travel, on an average, 4 miles an hour and 9 hours a day, how many days will be required to pass over 1260 miles ? Ans. 35. 20. How many bushels of barley at 75 cents per bushel, will be re- quired to [);iy a debt of ^45.75? Ans. 61. 21. How many days' work at 125 cents per day, will pay for 80 acres of land at 225 cents per acre ? Ans. 144, 22. What number, multiplied by 23, will give the same product as 75 multipUed by 691 " Ans. 225. 23. What number, multiplied by 16-^, will give the same product as 300 multiplied by 451 ? Ans. 8200. COMPOUND NUMBERS. (AuT. 25.) Compound Numbeus are such as express quantities consisting of different denominations, but of the same general kind, such as bushels, pecks, quarts, &c. ; yards, feet, inches, &C. The most proper appellation for these quantities is Denominnte Numbers, because they simply consist of dijftrcnt, denoniinutions, and are not comfiound ; but the name compound numbers has been so long at- tached to them that it would be dilncult to cliange it. The following Tables of the denominations of compound numbers are to lie committed to memory before entering upon reduction. ENGLISH MONEY. The denominations of English Money are, guineas, pounds, shil- lings, pence, and farthings. 4 firthings, marked far., make 1 penny, marked d. 12 pence 1 shilliiig, . . . s, 20 shillings 1 pound, . . . £. 21 shillings 1 guinea. 50 ARITHMETIC. MENTAL EXERCISES. In £2 3s., how many shillings ? In 2.S-. 2d., how many pence ? In 35. 2f/., how many pence 1 In £Z 2s., how many shillings ? It is evident, from the inspection of the table, that to change pounds to shillings we must multiply the£l by 20, and to change shillings to pence we must multiply the shillings by 12, &c. ; and this changing of a quantity from one denomination to another is called Reduction ,- for it is reducing. TROY WEIGHT. Gold, silver, jewels, and liquors, are weighed by this weight. Its denominations are pounds, ounces, pennyweights, and grains. TABLE. 24 grains, gr., . . . make 1 pennyweight, marked dwt. 20 pennyweights .... I ounce, oz. 12 ounces 1 pound, lb. MENTAL EXERCISES. In 2 pounds 1 ounce, how many ounces ? In 2 ounces 3 pennyweights, how many pennyweights? In 2 pennyweights and 2 grains, how many grains? In 1 pound, how many pennyweights ? In 1 ounce, how many grains ? APOTHECARIES' WEIGHT. This weight is used by apothecaries and physicians in mixing their medicines. Its denominations are pounds, ounces, drams, scruples, and grains. The pound and ounce are the same as the pound and ounce in the Troy weight; the difference belween the two weights consists in the different divisions and subdivisions of the ounce. TABLE. 20 grains, gr., make 1 scruple, marked g 3 scruples, 1 dram 3 8 drams, 1 ounce . . . . g 12 ounces, 1 pound .... lb AVOIRDUPOIS WEIGHT. By this weight are weighed all coarse articles, such as hay, grain, chandlers' wares, and all the metals, excepting gold and silver. Its denominations are tons, hundreds, quarters, pounds, ounces, and drams. 'i'he hundred weight is 1 12 pounds, as appears from the table; but at the present time the merchants in our principal cities buy and sell by the 100 pounds, and 20 hundreds a ton. TABLES. 51 TABI-E. 16 drams, dr., make 1 ounce, marked oz. 1 () ounces 1 pound, . . . . lb. 23 pounds, 1 quarter, . . , cp: 4 quarters, 1 Jmndred weight, cict. 20 hundred. , 1 ton, T. MENTAL EXERCISES. In 10 pounds, how many ounces ? \n 2 pounds 8 ounces, how many ounces ? In 3 pounds 2 ounces, how many ounces? Ill 10 ounces 10 drams, how many drams 1 In 100 pounds, how many ounces'? LONG MEASURE. Tii>i!sr measure is used when length only is considered. Its denomi- nations are degrees, leagues, miles, furlongs, rods, yards, teet, inches, and barley-corns. TABLE. 3 harlev-corns, bar., . . . make 1 inch, . . . marked in. 12 inche's, 1 foot, ff, 3 feet 1 yard, yd. 5h yards, or 16^ feet, 1 rod, perch, or pole, rd. 40 rods, 1 furlong, fur. 8 furlongs, or 320 rods, .... 1 mile, 7ni. 3 miles, 1 league, L. 60 geoi^raphical or 69A statute "> , , j o ° ° ^ ., ■'■ 5-1 decree, di:s^.ox° miles, 5 •••"•& orn 1 C a great circle, or circumference 360 degrees, < ° .. ,. => ' C ol the earth. [Note. A fathom is six feet, and is generally used to measure the depth of water. A hand is four inches, and is used to measure the height of horses.] MENTAL EXERCISES. How many inches in one yard ? How many inches in 2 feet 2 inches ? How many feet in 2 rods? How many feet in 2 rods and two feet? In 3 leagues and I mile, how many miles ] CLOTH MEASURE. Cloth measure is used for measuring all kinds of cloth. Its de- nominations are ells French, ells English, ells Flemish, yards, quar- ters, nails, and inches. 52 ARITHMETIC. TABLE. 2^ inches, in., make 1 nail, . . . marked na. 4 nails, 1 quarter of a yard, . qj: 4 quarters, 1 yard, yd. 3 quarters, 1 Ell Flemish, . . . E. Fl. 5 quarters, • 1 Ell English, . . . E.E. 6 quarters, 1 Ell French, . . ^ E. Fr. MEXTAL EXERCISES. In 4^ inches, how many nails ? In 2 quarters 2 nails, how many nails? In 3 yards 3 quarters, how many quarters ? In 2 yards 2 quarters, how many quarters? In i yard 2 nails, how many nails] LAND OR SQUARE MEASURE. Land or square measure is used in measuring land, or anything in which length and breadtli are both considered. TABLE. 144 square inches, sg. in., . . . make 1 square foot, . sq. ft. 9 square feet I square yard,., .sv^.j/q'. 30;^ square yards, 1 square pole, . F. 40 square poles, 1 rood, . . . A'. 4 roods, 1 acre, , . . . A. 640 acres, 1 square mile, . M. The surveyor's or Gunter's chain is generally used in surveying land. It is four poles, or 66 feet, in length, and is divided into 100 links. TABLE. 7jW inches make 1 link, .... marked /. 4 rods, or 66 feet, .... 1 chain, c. 80 chains 1 mile, mi, I squ ire chain, 16 square poles, . . . . P. 10 square chains, 1 acre, A. Land is generally estimated in square miles, acres, roods, and square poles or perches.* MtXTAL EXERCISES. In 2 feet square, how many square feet ? Ans. 4. i , r A surface 3 feet in length and 2 feet in width— how I j many square feet ? ' I i A surface 6 feet in length and 3 in width, how many i ' I square feet ? ♦More recently in mileB, acres, and decimals of an acre. TARLK 53 A towiishii) 6 miles long and 4 i miles ciiX's it coiitain '.' How many square miles in 10 miles square ] bruat!, how many square SOLID OR CUBIC MEASURE. 8olid or cubic measure is used in measuring such things as have three (limensions, of length, breadth, and thickness. Its denomina- tions are tons, cords, yards, feet, and inches. 1728 solid inches, s. in., . . '27 solid feet, • 40 feet of round, or ') 50 feet of hewn timber, 5 make 1 solid fool, marked s. fl, s- yd. 1 solid yard, . I ton, . Ton. 12S solid feet=8X4X't, that is, ~) a pile 8 feet in length, 4 feel in > 1 cord of wood, . . C. width, and 4 feet in height, ^ [NoTK. A cord foot is 1 foot in length of the pile which makes a cord. It contains 1 6 solid feet.] MENTAL EXERCISES. A block 1 foot long, 1 wide, and 1 high, is a cubic foot. A block 1 foot square at the end and M feet long, how many cubic feet? A block containing 4 s([uare inches at the end and 10 inches bng, how many cubic inches? WINE MEASURE. Wine iriejisure is used in measuring ail liquors, excepting beer and ale. Its denominations are tuns, pipes, hogsheads, barrels, gallons, quarts, pints, and gills. TABM-. 4 trills, o-,-'., 2 pint.s,\ . 4 quarts, . 3 4 gallons, . 63 gallons, . make 1 pint, . . . 1 quar ; gallon, . 1 barrel, . I hogshead, 2 hogsheads, 1 pq;e. 2 pipes, or 4 hc)gsheads, . . . tun, marked pt. . . . gt . . . gal. .... oar. . Md. . pi. tun. A wine gallon contains 23 1 cubic inches. MENTAL EXERCISES. In 2 pints, how many gills ? In 3 pints 1 gill, how many gills? In 3 gallons, how many quarts? In 3 gallons, 2 quarts, I pint, how many pints? In 1 gallon 1 pint, how many pints ? 54 ARITHMETIC. ALE OR BEER MEASURE. Ale or beer measure is used in measuring ale, heer, and milk. Its denominations are hogsheads, barrels, gallons, quarts, and pints. TABLE, 2 pints, pt., make 1 quart, . . marked qt. 4 quarts, 1 gallon, gal 36 gallons, i barrel, bar. 54 gallons, 1 hogshead, . . . hhd. A gallon, beer measure, contains 282 cubic inches. DRY MEASURE. Dry measure is used in measuring all dry articles, such as grain, fruits, roots, salt, coal, &c. Its denominations are caldrons, bushels, pecks, quarts, and pints.] TABLE. 2 pints, pt make I quart, . . . marked qt. 8 quarts, 1 peck, pk. 4 pecks, 1 bushel, hu. 36 bushels, .... • 1 caldron, cul. [Note. A gallon; dry measure, contains 2684 cubic inches. A Winchester bushel is 18^ inches in diameter, 8 inches deep, and con- tains 21501 cubic inches. 5 A bushel of coal, lime, &c., is 2688 cubic inches. TIME. TABLE. 60 seconds, sec, make 1 minute, . . marked mm. 60 minutes, 1 hour, h. 24 hours, 1 day, d. 7 days 1 week, w. 12 months, (or 365 days,) ... 1 year, y, [Note. The true year, according to the latest and most accurate observations, consists of 365 days, 5 hours. 48 minutes, and 58 seconds ; this amounts to nearly 365^ days. The common year is reckoned 365 days, and every fourth or leap year one day more. Those years which are divisible by 4, without remainders, are leap years. By estimating 5 hours, 48 minutes, 58 second:=, as 6 hours, accumulated an error, which amounted to more than 1 1 days in 1752 ; and the II days were dropped to correct the style : hence, before that period is called Old Style, subsequently New Style. A further correction of one day took place in' the year 1800 ; still a further correction will take place in the year 1900, after which there will be no correction for 200 years.] REDUCTION. 55 MENTAL EXERCISES. In 2 hours 10 minutes, how many minutes? In 3 minutes 10 seconds, how many seconds? In 10 hours, how manyminutesl In three hours, how many minutes? how many seconds? In 2 hour.--, how many minutes? In 13 minutes 3 seconds, how many seconds 1 CIRCULAR MEASURE, OR MOTION. Circular measure is used in calculating latitude and longitude, and also in measuring the motions of the heavenly bodies. Every circle is supposed to be divided into 360 equal parts, called degrees. TABLE. 60 seconds (") make 1 minute, , . marked 60 minutes, 1 degree, " 30 degrees 1 sign, s. 12signs, or3()0° 1 circle c. The signs are becoming obsolete. 'l"he best astronomers of the present day do not use them. MENTAL EXERCISES. In 1 sign 10 degrees, how many degrees? In 2 degrees, how many minutes? In 3 degrees 3 minutes, how many minutes ? In 2 signs 2 degrees, how many degrees ? How many minutes in a quadrant, or 90 degrees? PARTICULARS. 12 units make a dozen. 12 dozen, a gross. 144 dozen, a great gross. 20 units, a score. 24 sheets of paper, a quire. 20 quires, a ream. BOOKS. A sheet folded in two leaves is called a folio. folded in four leaves .... a quarto, or 4to. '< folded in eight leaves ... an octavo, or 8vo. " folded in twelve leaves ...ad lodecimo, or 12mo. •* folded in eighteen leaves . . an 18mo. REDUCTION". (Art. 26.) Redcctiov is reducing or changino; one dcnomina. tion of any quantity to another denomination, without changing its 56 ARITHMETIC. real value; and it invoivos no other principles than those called out ill the mental exercises under the tal-.les. From these exercises we );erceive that quantities may be reduced from a higher to a lower denomination, l»y mnltiphcation. Thus, 2 yards are 6 feet: these, reduced to inches, give 72. Conversely, lower denominations may be brought to higher, by division, as pounds to qu irlcrs, hundreds weight, or tons. In all these cases, the quantity remains unchanged, although it is expressed in a diflrrcnt denomination. When higher denominations are to be reduced to lower, the expla- nation gives the following r?iTT,K. Mnlliply iJie successive denominafions, comincndns; iciih Ihe hig.'ie-f given, by the number iliai ivill make if one of the next hncer, adding, in their proper placea, ihe several inferior denomina- tions expressed in the given number. When lower denominations are to be reduced to higher, the expla- nation gives the following Rule. Divide the given denomination by the number that will make one of the next higher,- and the quotient thence arising by as manyas7nake one of ike denomination next above that, and soon to ihe required one. The farmer of these rules is reduction descending, the latter ascending. Being reverse operations, they pnjve each other. As the principles of the operation are the same under each table of weight, measure, or motion, we shall give the examples promiscuously, to exercise quickness of thought. 1, Reduce 17 lbs. W oz. 15 diets., to pennyweights,* nibs. : 1^ cz. :o4 1 1 oz. added. In this example, we first multiply by | the number of ounces in a pound, and 215 then add the ounces, &c,, «Scc. 20 dwi. 4300 15 dwts. added. 4315 dwts. * A practical man would at once perceive that this is 5 pennyweights less than 18 pounds : therefore, 18 X 12X20— 5=the result. REDUCTION 57 2. In 2.') l/js. 9 oz. f/a'/i^ 10 gr., how many grains? Ans. 148330. 3. RediJCfi 7461 fi farthings to pounds. 4) 71016 12)18654 pence. 20)1554 shillings and 6 pence. 77 and 14 shillings over. Am. £77, 145. 6d=746 16 farthings. 4. In 3278 nails, how many yards? 4)3278 We first divide by 4, which brings the number to quarters, and then again by 4, which brings it to yards. 4)819 . 2 n«. 204 . 3 qrs. A)ts. 204 yds. 3 qrs. 2 7ia. 5. In £1234 155. 7c?., how many farthings? £ s. d. '234 15 7 20 24695 shillings, 15 being added in mentally. 12 296317 pence, 7 being added in mentally. .4/15. 1185388 farthings. 6. Reduce 3060288 cubic inches to tons of round timber. 1728)3060288(1771 We first divide by 1728, the num- ber of solid inches in a solid foot, and next by 40, the number of solid feet in a ton 410)177(1 44 1 1 1728 13322 12096 12268 12096 1728 1728 Ans. 44 tons 11 feet. 58 ARITHMETIC. 7. Reduce 43 gallons 3 quarts 1 pint, to pints. 43 4 175 Ans. 351 pints. (AiiT. 27.) 8. Reduce 35 tons to drams. When there are no inferior denominations, as quarters, pounds, &c., to add in as the operation advances, we may arrange all our multi- pliers before the eye, and take the product of several of them men- tally, to shorten the operation. In the present example we multiply 35 tons by 20 by 4 by 28 by 16 by 16 Then, 78400 by 256 gives the answer. 35X20=700 4X28=112 16X16=256 470400 3920 1568 20070400 9. Reduce 23 bushels 3 pecks 5 quarts 1 pint, to pints. N. B. This is 5 pints less than 24 bushels ; therefore, if we reduce 24 bushels to pints, deducting 5, we have the answer. Multiply 24 by ■' 4 by 8 by 2 10. Reduce H acres 3 roods 15 rods, to rods. Ans. 1895. 1 1. Reduce 24 square rods to square feet. Ans. 6534. 12. Reduce 10 pipes 1 hogshead and 2 quarts of wine, to pints. Ans. 10588. 13. Reduce 3 hogsheads to gills. Ans. 6048. That is . . . .... 64 by . . . . 24 128 256 1531 Ans. REDUCTION. 59 14. In 1746880 ounces, how many tons, Ans. 48 tons, and 14 cwt. 3 qrs. 8 lbs. over. 15. In 17645 grains, apothecaries' weif^ht, iiow many pounds ? Ans. 3 Ib.s., and (i dr. scru. 5 grains over. 16. In 168474 feet, how many miles'! An'\ 31 n)iles, and 7 fur. 58 yds. over. 17. In 2419200 seconds, how many daysl '" Ajis. 28. 18. In 547325 fartliings, how many pence, shillings, and pounds? Ans. £579 2s. Gii. 1 qr. 19. In 9173 nails, how massy yards? Ans. 573 yds. 1 qr. 1 n. 20. How many barleycorns will reach rovnid the earth, supposing it, according to the best calculations, to be 24877 miles ? A}is: 4728G20160. 21. How many seconds are in a solar year, or 365 days 5 hours 48 minutes 58 seconds? Ans. .j1556938. 22. In a lunar month, or 29 days 12 hours 44 minutes 3 seconds, how many seconds] A7is. 2551443. 23. In an ingot of silver weighing 6 pounds 3 ounces 10 gnins, how many grains? Ans. 36010. 24. In 5 hundreds 2 quarters 16 pounds, how many pounds ? Ans. G32. 25. In 4 miles 6 furlongs 22 rods, how many rods ? Ans. 1542. 26. In 11456 geographic miles, how many degrees ? Ans. 190 deg. 56 min. 27. In 164736 inches, how many miles'? Ans. 2 miles 4 fur. 176 yds. 28. In 14764 nails of cloth, how many yards ? Ans. 922 yds. 3 qr. 29. In 2746 quarters, how many ells English ? A71S. 549 ells 1 qr. 30. Reduce 2 tuns to gills. Ans. IG\28. 31. Reduce 32 gallons 3 quarts to pints. Ans. 262. 32. Reduce 2 hogsheads 27 gallons 3 quarts, to quarts. Ans. 615. 33. Reduce 3 tuns I hogshead 15 gallons 1 quart, to pints. Ans. CG74. 34. Reduce 1484 yiints to gallons. Ans. 185 gal. 2 qts. 35. Reduce 167000 gills to barrels of 32 gallons each. Ans. 163 barrels 2 gals. 3 qfs. 36. Reduce 6272640 square inches to acres. Ans. 1. 37. A grocer purchased 16 hundred weight 3 quarters 20 pounds of sugar ; how many pounds are there in the whole? Ans. 1896. 33. A tobacconist bought 116 hundred weight 3 quarters of tobac- co; how many pounds were in the whole ? Ans. 13076, 39. A silversmith has 7 pounds 10 ounces of silver; how many grains are in the whole ? Ans. 45120. 40. An apothecary has several sorts of drugs, weighing toj^ether 47 pounds 6 ounces 4 drams; how many scruples and grains arc in the whole? Ans. 13692 scru., 273810 grs. 60 ARITHMETIC. 41. A merchant wishes to ship 300 bushels of flaxseeJ in casks con- taining 7 bushels 2 pecks each ; what number of casks are required 1 Atis. 40. 42. A certain barn is 64 by 36 feet, and 20 feet high ; another bam is 32 by 24 feet, and 16 feet high: how much larger is the former than the latter ? (8ee solid measure.) Ans. 3^ times larger. 43. How many times will a wheel 16 feet 6 inches in circumfer- ence, turn round in running 42 miles ? A/is. 13440 times. 44. There are two places on the equator, one in longitude 40 deg. east of the meridian of Greenwich, tlie other 30 deg. west; what is the number of geographical miles between them ? An.^. 4200. 45. A ship, during 3 days of storm, had changed her longitude 273 geographical miles ; how many degrees and minutes of a degree did she change ] Ans. 4 deg. 33 min. 46. How many quires and reams of paper are in 500520 sheets ? Ans. 20855 quires, 1042 reams 15 quires. 47. A printer calls for 4 reams 10 quires and 10 sheets of paper to print a book ; how many sheets does he call for ? Ans. 2170. 48. How many solid inches are in a solid 7 inches long, 7 inches wide, and 7 inches high 1 Ans. 343. 49. How miny solid inches are in a solid 2 feet 1 inches long, 6 inches wide, and 6 inches high 1 Ans. 27X30. 50. How many solid inches are in a solid 3 .feet 2 mches long by 2 feet 2 inches wide and 1 foot 8 inches high? A?is. 38X26X20=19760. 51. How !n;»ny yards of carpeting, 1 yard wide, will be required to carpet a room 18 feet wide and 20 feet long? Ans. 40. -^COMPOUND ADDITION. (Art. 28.) Compound Addition is simple addition and reduc- tion combined ; but we shall be more clearly comprehended through the mi'dium of an example. What is the sum of £19 15s. 8d., £27 18s. 6d., £43 9s. 4d., and £7 6s. 6;]. As unlike things cannot be added together, (.\rt. 5.) we must write pounds under pounds, shillings under shillings, and pence under pence, thus: £ s. d. 19 15 8 27 18 6 7 6 6 55 8 UKDUCTION. 01 Tn'ow, each column, by itself, is a sum in t-implc !i roluuu^. 'J'he I shilling, added in with the other shillings, all make 40 shillings; which, reduced, make 2 pounds and shillings over. The 2 pounds, added into the column of pounds, make the whole number of pounds 55; and the several sums of money make the total sum of £55 Os. 8d. If the pupil retains the principle, that compound addition is simple addition and reduction combined, no rule for addition will be required ; but for the sake of conciseness, we give the following Rule. 1. Flace the numbers so, that those of the same denomi- nation will stand directly under each other, and in distinct and sepa- rate columns. 2. Add up the Jis;iires in the lowest denomination, and find, by reduction, how many units or ones of the next higher denomination are contained in their sum, 3. Set down the remainder below its proper column, and carry those units or ones to the next denomination, which add up in the same manner as before. 4. Proceed thus through all the denominations, to the highest, whose sum, together with the several remainders, luill give the answer sought. N. B. The method of proof, rather a test, is to vary the order of addition : that is. break the sum into several sums, and then take the partial sums for the sum total ; and if two methods give the same sum total, that sum may be regarded as correct. ENGLISH MONEY. £ s. d. 48 13 8 51 6 4 67 11 3 76 18 10 244 10 1 EX A MPLE s. £ . 19' 42" Take 121^ 37' 50" Rem. 37° 39' 39" A person residing in latitude 27" 32' 45" north, wishes to visit a place 52° 24' 18" north ; hou' many degrees, minutes, and seconds northward must he travel? Ans. 24° 51' 33". y. m 6 9 1 6 5 3 TIME. w. d. h. m. sec. 3 I 2;? 40 20 2 6 12 57 36 y. m. d. h. 9 8 24 47 6 4 19 39 From 900 years take 1 1 1 years and 6 months. Ans. 788 yrs. 6 m. If T take 1 year 1 month from 6 years, what space of time will still remain ? Ans. 4 yrs. 1 1 m. _ 6G ARITHMETIC. CLOTH MEASURE. yd. qr. na. E. Fl. qr. na. E. En. qr. na. 35 1 2 467 3 1 765 1 3 19 1 3 291 3 2 149 2 1 N. B. We deem it unnecessary to give formal examples corres- ponding to all the tables of weights and measures, as the principles of one apply to all. ArPLICATIOX. 1. From 3 pounds 8 shillings and 3 pence, take I pound 7 shillings and 9 pence. Ans. £2 Os. 6d. 2. From 4 pounds 4 pence, take 19 shillings 5 pence. yl;js. £3 0s. Ud. 3. From 7 pounds, take 20 grains Troy. Alls. 6 ll)s. II oz. 19 dwts. 4 grs. 4. From 9 tons 9 hundred weight, lake 2 tons 3 hundred weight 3 quarters and 3 pounds. Ans. 7 T. 5 cwt. qrs. 27 lbs. 5. From 3 years 4 months 20 days 16 hours, take 1 year 5 months 21 days 14 hours. ' Ans. 1 yr. 10 mo. 28 d. 2 h. 6. What interval of time elapsed between July 12th, 1827, and November 17tli, 1831? Ans. 4 yrs. 4 mo. 5 d. 7. What is the interval of time between December 23d, 1798, and February 21st. 1811 ? Ans. 12 yrs. 2 mo. 28 d. 8. 'J'he apparent revolution of the sun is 365 days 5 hours 48 min- utes 58 seconds, that of the moon is 27 days 7 hours 43 minutes 3 seconds ; what is the difference ? Ans. 337 d. 2L h. 5 m. .'J4 sec. 9. What is the difference of longitude between two places, one 75° 21' 30" west, and another 71° 20' 3.5" west? Ans. 3° 51' .55". 10. What is the difference of longitude between two places, one situated 3° 4' '20" east of an assumed meridian, and the other 1° 20' 2" west of the same 1 Ans. 10° 24' 22". 11. What is the difference of latitude between two places, one latitude 5"^ south, the other 5° north ? Ans. 10°. 12. What is the difference of cold between 3° below zero, and 10° above? Ans. 13°. N. B. The last three problems have the algebraic peculiarity of subtraction, the line of demarcation being between them. COMPOUND MULTIPLICATION. (^Art. 30.) CoMPOuxD MuLTiPLTCATToy IS thc same in relation to simple multiplication, as compound addition is to simple addition : that is, each denomination of the multiplicand is a sum in simple COMPOUND MULTIPLICATION. 67 multiplication, and its product may require reduction. Il is, Ihtre- fure, simple mull ipUcation and reduction combined. From the above principle, the pupil will recognise the rationale of the following Rule. 1. Set down the coinpaund sum to be miilliplied, and un- der its lowest denomination at tlie right hand set the multiplier. 2. Multiply the number in the lowest denomination by the mul- tiplier, and find how many units of the next higher denomination are contained in the product, setting down what remains. 3. In like manner multiply the number in the next denomina- tion, and to the product carry or add the units, before found, and find how many xmits of the next higher denomination are in this amount, which carry in like manner to the next product, setting doiun the overplus. 4. Proceed thus to the highest denominatio7i proposed : so shall the last product, ivilh the srceral remainders, taken as one common number, be the whole anh/unt required. The method of procf i^ the same as in simple multiplication. EXAMPLES. bu. pk. qf. pt. 7 2 5 11 7 times I pint make 7 pints ; 2 pints make 1 quart ; then, 7 pints make 3 quarts, and leaves 1 pint. Set down the 1 pint, and carry 53 2 6 1 the 3 quarts to the product of the next figure. 7 times 5 quarts make 35 quarts, to which add the 3 quarts, which make 38 quarts; 8 quarts make 1 peck; then 38 quarts make 4 pecks, and leaves 6 quarts. Set down the 6 quarts, and carry the 4 pecks. 7 times 2 pecks make 14 pecks ; add the 4 pecks, and it makes 18 pecks. 4 pecks make 1 bushel ; then, 18 pecks make 4 bushels, and leaves 2 pecks. Set down the 2 pecks, and carry the 4 bushels. 7 times 7 bushels make 49 bushels ; add the 4 bushels, and it makes 53 bushels, which set down, and the work is done. bu. pk. qt. pt. bu. pk. qf. pt. y 3 6 1 23 2 5 1 5 8 49 3 1 189 1 4 In 1 vessel are contained 29 bushels 2 pecks and 5 quarts ; how many in 9 such vessels ? Ans. 266 bu. 3 pk. 5 qt. Observation. When the multiplier is more than 12, and a com- posite number, we may multiply first by one factor, and that product by the other; or, if the multiplier has more than two simple factors, such as 72, which is the product of 2X4X9, we may multiply 68 ARITIliMETIC. by the (^ilT^•rpnt factors in succrssion, no matler which we take first; though it is generally more expedient to take the largest first. Orseiivatiox SKcoxn. When the multiplier is not a composite number, such as 23, we may take the sum 24 times, by multipiyitig by (i, and that product by 4, and then subtracting once the sum, which will leave 23. If the multiplier be 31, we may multiply by 10 and 3, and after- wards add once the number, &c. APrLICATlON. 1. What is the cost of 9 hundred weight of chee-se, at 1 pound 11 shillings and 5 pence per hundred weight ? Aris. £14 2s. 9d. 2. A merchant has .3 chests of tea, each weighing 3 hundred weight 2 quarters and 9 pounds ; what is the weight of the whole? Ans. 10 cwt. 2 qrs. 27 lbs. 3. If a man drink I pint 2 giljs of ale per day for 29 successive days, what quantity will he have drank in all? Alls. 5 gal. 1 qt. 1^ pt. 4. If a soldier's ration of bread be 5 pounds 6 ounces 8 drams per week, what will it amount to in 52 weeks? Ans. 2 cwt. 2 qrs. 1 lb. 2 oz. 5. A merchant bought 9.5 pairs of shoes, at 4 shillings 6 pence and I quarter a [)air ; how much did he pay for the whole ] £21 9s. 5Jd. 6. A gentleman bought 43 silver spoons, each weighing 2 ounces 14 pennyweights and 6 grains; what was the weight of the whole? Ans. 9 lbs. 8 oz. 12 dwts. 18 gr. 7. How many yards of cloth in 35 pieces, each containing 27 yards 3 quarters 2 nails ? Ans. 975 yds. 2 qrs. 2 na. 8. A silversmith has 7 tankards, each weighing 3 pounds 4 ounces pennyweights and 22 grains; what is the w^eight of the whole? Ans. 23 lbs. 4 oz. 6 dwts. 10 gr. 9. If a man can perform a piece of work in 2 years and 3 months, how long would it take him to perform 5 such pieces ? Ans. 11 yrs. 3 mos. 10. If a laborer dig a drain in 2 weeks and 3 days, how long a time would he require to dig 9 such drains? Ans. 21 w. 6 d. 41. It is found by oKservation that the sun, on an average, changes his longitude 0° 59' 8" 33 per day ; how much will he change in 10 days? how much in 30? how much in 300? how much in 365? ■^ 9 51 23 3 . I 29 34 9 9 ^^^' f295 41 39 J 359 45 40 45 COMPOUND DIVISION. 69 N. B. In this example, 8'' 33 is 8 seconds and 33 hundreds, the 33 being decimals. But we have ni)t yet exercised in decimals ; and as thev increase and decrease on iht same ncaU as abstract numbers, we do not tiesilate to introduce them thus incidentally. In the table of circular motion, the pupil will lind signs, degrees, and minutes; but the stilus arc no longer rdained in pruc/icul use ,- however, through superstition and old custom, signs will long retain their places in common almanacs. 12. The moon moves 13*^ 10' 35" in one day, how many degrees, minutes, and seconds, will she move in 17 days ? 4X4-1-1=17 13° 10' 35 In 4 days it moves 52 42 20 4 In 16 days it moves 210 49 20 In 1 day it moves 13 10 35 la 17 days it moves 2-i3^ 59' 55'' Ans. 1:3. The planet Jupiter changes its longitude 4' 59" 2 in one day how much will it change its longitude in 59 days? Ans. 4° 54' 18". 14. The planet Saturn changes its longitude 2' 0" 91 in one day how much will it change in 3ti5 days ? Ans. 12° 15' 37". / COMPOUND DIVISION.. (AnT. 31.) CoMPOUxVD Division — the reverse operation to com- pound multiplication, and, in its general principle, the same as simple division. As in simple division, we must divide the highest number of the dividend as a simple number, by the divisor ; and the remainder must be reduced to the next lower denomination, and the number standing in that denomination being added in, we have a new dividend to be divided asa simple number ; and so on through all the denominations. This obvious operation gives us the following RuLK. Place the divisor on the left of the dividend, as in simple division. 1. Begin at the left hand, and divide the number of the highest denomination by the divisor^ setting down the quotient in its proper place. 2. If there be any remainder after this division, reduce it to the next lower denominal/on, which, add to the number, if any, belong- ing to that denomination, and divide the sum by the devisor. 70 ARITHMETIC. 3. Set down cs;uin this quotient, reduce its remainder to the next h)wer dtnominalion again, and so on through all the denominations to the last. N. B. Compound division and compound multiplication prove each other. EXAMPLES. 1. Divide 19 pounds 17 shillings and 6 pence equally among 6 men. Here we say, 6 in 19 is contained 3 times, and 1 pound over, which, reduced to shillings, and 17 added, make 37 shillings, which, divided by 6, is contained 6 times, and 1 shilling over, which is 12 pence, and the 6 added is 18, which, divided by 6, gives 3 pence, bushels 2 pecks 6 quarts 1 pint equally among Here 7 into 25 bushels 3 times, and 4 re- mains. Set down the 3. Reduce the 4 bushels to pecks, which makes 16 pecks: add 16 pecks to 2 pecks, it makes 18 pecks. Now, 7 into 18 pecks 2 times, and leaves 4. Set down the 2, &c. 3. Divide 821 pounds 17 shillings and 9^ pence by 4. Ans. £205 9s. 5d. 3 far. 4. Divide 55 pounds 14 shillings and | pence by 7. Ans. £7 1 9s. Id. 32 far. 5. A farm containing 746 acres 3 roods 29 poles, is to be divided equally between 9 heirs; what is the share of each 1 ^ A7is.82 A. 3R.$8^ P. 6. Divide 3 acres of land into 8 village lots ; what number of poles will each lot contain? Am^. 60. 7. Divide 3 acres of land into lots, each lot containing 3 roods ; bow many lots will there be ? Ans. 4. 8. Divide 1 acre 1 rood of land into 10 equal parts; how many poles will each part contain ? Ans. 20. 9. Put 23 bushels 1 peck of wheat into 10 bags ; how much must each bag hold ? Afis. 2 bu. IJL pk. 10. Divide 10 gallons and 3 quarts into 6 equal portions: what will each portion be] Ans. 1 gal. 3 quarts ^ pt. (Anr. 32.) When the divisor is over 12 and is a composite number, that is, one consisting of two or more simple factors, we may divide as in short division, first by one factor, and that quotient by another, &c. But when the number is prime, having no simple factors, we divide by the whole number at once, after the manner of long division. Thus. £ s. d. 6)19 17 6 3 6 3 2. Divide 25 I persons. bu. pk. r^t.pf 7)25 2 6 1 3 2 5 1 COMPOUND DIVISION. 71 6. Divide 79 buslicls 1 peck 7 quarts by 23. hu. pk.qt. bu. ph. qt.pt. 23)79 17(3171 69 — 4X10=40, and 1 peck aJded makes 41, &c. 10 4 23)41(1 peck. 23 18 23)151(6 quarts. 138 13 2 23)26(1 pint. 23 Rem. 3 pints. 7. A boat load of corn, containing 4927 bushels 3 pecks, is owned equally by 29 persons ; what is the share of each? Ans. 169 bu. 3 pk. 5 qt. 1 pt., and I pt. rem. 8. Divide 542 pounds 7 shillings and 10 pence by 97. Ans. £b Us. lOd. 9. Divide 123 pounds II shillings 2^ pence by 127. Ans. £0 19s. 5^d. 10. Divide 330 hundred weight 3 quarters by 14. A>u.2ri cwi. 3 qrs. 18 lbs. 11. If 35 pieces of cloth, of equal quality, contain 971 yards and 1 quarter, how many yards in a piece ? Ann. 27 yd. 3 qr. 12. If 259 acres 1 rood 10 rods of land be divided into 36 equal lots, how much land will be contained in a lot ? Ans.t A.OTi. 32^ r. 13. If 56 pounds of butter cost 4 pounds 18 shillings, what is it per pound? Ans. Is. 9d. 14. Divide 124 pounds 5 shillings and 4 pence into 32 equal parts. Ans. £3 17s. 8d. 15. Divide 336 bushels 3 pecks 4 quarts by 70. Ans. 4 bu. 3 pk. 2 qt. 16. Divide 336 bushels 3 pecks 4 quarts, by 4 bushels 3 pocks and 2 quarts. Ans.lQ. Reverse the preceding problems, taking the answers for divisors, 72 ARITHMETIC. and the former divisors will be quotients; but to effect the division, reduce all to the lowest denomination mentioned, and divide as in sim- ple division. If more clear, we may enunciate the 16th example thus: A farmer has 336 bushels 3 pecks 4 quarts of wheat in his granary, which he wishes to put in casks to send away, each cask containing 4 bushels 3 pecks and 3 quarts ; how many casks will be required ? Ans. 70 casks. The operation is thus: hu.pk. qt. hu. ph. qi. 4 a 2 ) 336 3 4 ( 4 4 19 1347 8 8 154 ) 10780^70 Ans. 10780' 17. A certain secret association in Ireland paid a bill of j£4 18s., by assessing its members Is. 9d. apiece ; how many members were there ? Alls. 56. N. B. This is but a variation of example 13 ; and in like manner every example, up to 16, may be varied. 18. I have a pitcher which holds 2 quarts and 1 pint; how many times can it be filled from a barrel of cider, which holds 31 gallons 2 quarts ? Ans. 502^ 19. How many times will 13 bushels fill a vessel which holds 1 quart 1 pint and 1 gilH Ans. 256 times. 20. How many suits of clothes, each requiring 3 yards 1 quarter and 2 nails, can be made from a roll of cloth containing 27 yards ? Ans. 8. MISCELLANEOUS EXAMPLES, Applicable to the preceding principles. 1. At 5 cents a quart, what will 5 bushels cost? Ans. §8. 2. At 3 cents a pint, what will 3 pecks and 6 quarts cost '\ Ans. 90 cents. 3. At 5 cents a pint, how many gallons can be bought for 10 dollars? Ans. 25. N. B. As the pupil has been instructed from the very first of this work, from simple addition, that 10 mills make a cent, 10 rents make a dime, and 10 dimes make a dollar, and that these denominations are the same in order as the order of simple numbers; therefore, the re- duction from dollars to cents is to multiply by 100; dollars into mills. COMPOUND DIVISION. 73 multiply by 1000; and reduction the other way is to divide by these numbers. Some arithmetical writers have treated Federal Monei/ as conipmtnd numbers, ami have gone throui^h all the formality of reduction — addi- tion, subtraction, multiplication, and division of federal money — the same as they do the really compound numbers, pounds, shillings, and pence. But, federal money was purposely adjusted to the rcuk nf simple numbers ,- and if it is now proper to treat these denominations as compound, we must suppose the design not accomplished. Federal money belongs to whole numbers and decimal fractions ; and the sub- ject must be incomplete until we pass decimal fractioris. Example 3, and most of the examples here inserted, should be done by canceling, as explained in article 21. 4. At 8 cents a gill, how many gallons will 12 dollars purchase? Aris. 4l;. .5. What will 10 ounces 10 pennyweights cost, at 15 cents a pen- nyweight ? * Ans.$-M.50. 6. At 20 cents a square rod, what will 2 acres 3 roods of land cost? Ans.$fi8. 7. At $2 a square rod for land, what must be paid for a village lot 12 rods long and 5-| rods wide ] Ans. S132. 8. In 11 bars of gold, each containing 5 pounds 3 ounrcs 2^ pen- nyweights, how many grains ? Ans. 23:]!^8\ 9. At 5 cents an ounce, what will 10 p.v.inds i ounces of copper cost ? A71S. iS.2(). 10. IIov.- many kegs, each holding 4 traiions 2 .juarts, can be filled from a liogshead containing G3 gallons ] Aus. 14. 1 1. .'\.t 6^ cents a quart, what will 6 bushels atul 1 peck cost ( Anf,: $12.r)0. 12. How much will 4 barrels of molasses cost, at 4 cents a pint. Any. $10.08. 13. Divide 2 hours 10 minutes by 5 minutes 5 seconds. Ans. 2^^. 14. How many times is 13° 20' contained in 360° ? Ans. 27 times. 15. If the moon moved 13° 20' in 1 day, how many days would it require to make a revolution nf 360° ] An.^. 27 days. leXlf Jupiter changed its longitude 5 minutes of a degree, as seen from the sun, bow many years, of 3^60 days each, would it require to make a revolution ? - O " Ans. 12. 17. At 8 cents a pint for wine, how many gallons can be bought for 40 dollars? Ans. 6-2^. 18. At 10 cents a nail, how many yards of cloth can be buu^du for 16 dollars? ' J/?.v."]0. 19. At 12^ cents a quart, how many gallons can be bought for 12 dollars? Ans. 24. 74 ARITHMETIC. 20. How many little squares, 3 inches long and 3 inches wide, can be cut from a square yard of paper? Ans. 144. 21. How many bottles, each containing 1 quart 1 gill, will be re- quired to draw off a barrel of cider containing 3U gallons! 'Ans. 112. 22. Divide 421 pounds 14 shillings and 8 pence among 3 men, 5 women, and 7 boys, and give each man double of the sum given to a woman, and each woman 3 lanes the sum given to a boy ; how much IS tne share ct ^ each ? Ans. Each boy must have £10 10s. Each woman, . ... 31 12s. Each m.an, 63 53. I0|d. 7id. 2|d. The art of working the preceding problem consists in obtaining the divisor, which is 40. 23. A man bought a chaise, horse, and harness, for 70 pounds. He gave twice as much for the horse as for the harness, and twice as much for the chaise as for the horse ; what did he give for each ] A}is. Harness £10. 24. A farmer sold some calves and some sheep for 108 dollars; the calves at 5 dollars, the sheep at 8 dollars apiece ; there were twice as many calves as sheep, — what was the num.ber of each sort? Aus. 6 sheep and 12 calves. 25. The planet Jupiter changes its mean longitude 4° 54' 18'^ in 59 days; how far will it change in one day ? Aus. 4' 59" 2. 26. The moon is observed to move over 197° 38' 45" in 15 days; how far will it move in one day ? Ans. 13° 10' 35", 27. In 365 days, the planet Saturn will change longitude 12° 15' 37" ; how much will it change in one day ? A^7is. 0" 91. 28. If the apparent. motion of the sun be 59' 8" in one dav, how many days will it require to make a revolution of 360°? Ans. 365|||. 29. 'I'he moon changes her longitude 13° 10' 3.5" in one day ; how many days, then, will be required to make one revolution ? Ans. 27 d. 7 h. 43 m. 30. If Venus changed her longitude, (as seen from the sun,) 1° 36' per day, what, then, would be the time of her revolution 1 Ans. 225 days. FRACTIONS, SECTION III. FRACTIONS. (Art. 33.) A part of any one thing is called ;\ fracjion. If an api.li', f)r instance, be divided into 3 equal parts, each part will he ont-thlrd, written thus, 5. If it be divided into 4 equal parts, each part will be onc-fuurlh, wriiten \. !f divided into 5 equal parts, each part will bo \ ; two of these parts must be written 1. i bu.-, generally, a fraction must be expressed by two numbers one a!)ove another. The lower number denotes the number of equal part;^ into which the unit is divided. The upper number shows how many of these equal parts are taken. ileiu-e, as the lower number of a fraction denotes or decides the den:»ii'iiat;()n, whether it be thirds, fourt/iy, ffths, or any other number, it is called the denominator. 'i'l'.e ur)per number is called the nunjf/Y//or, because it shows the number 1 if parts taken. (A;tT. 31.) A fraction may be considered as the result of an im- possible division. Thus, 1, one thing, or ujiity, divided into 5 equal parts, we write I above and ^ under it, or 1. 'J'hree times this is | ; or, we may consider 3 divided by 5, the quotient is 1. Hence, the denominator of a fraction may he considered as a divisor, and the numerator as a dividend, and the fraction itself as the result, or quotient, to an example in division. When the dividend and divisor are equal, the quotient is 1 ; that i.s, whiMi the numerator and denominator are equal, we have the whole of the thinij;, the whole as an aggregate or unit. (Art. 35.) When any fraction is before us, as f, we judge of its value by comparing its numerator with its denominator ; if the nu- merator is e^iual to the denominator, as we have just observed, tlie value of the fraction is 1 ; if the numerator is nearly equal to the de- nominator, the value of the fraction is nearly I ; if the numerator is one-half of the denominator, the value of the fraction i.s one-half. Hence, 1 is the same as ^. 6 (Art. 3fi.) As the value of a fraction depends upon the relation of the numerator to the denominator, and as tliis relation is not changed bv dividing both numbefs by the same divisor, we may, there- 76 ARITH3IETIC. fore, divide both numerator and denominator by any number that will divide them without a remainder, and the value of the fraction will not be changed.* EXAMPLES. 1. Reduce Li to its lowest terras. Ans.^. - 4 Here, it is evident that we can divide both numerator and denomi- nator by 6, making the fraction |, which is equal to li. 2. Reduce il to its lowest terms. Ans. f. 5 6 3. Reduce _3JL to its lowest terms. An^. ^. When the terms of the fraction are large, we may not bring it to its lowest terms by one division only, but we may divide the quotients ob- tained continually until no number greater than 1 will divide both of them \Nithout a remainder. 4. Reduce Ll^ to its lowest terms. 7 3 5. Reduce 1?.^ to its lowest terras. 2 4 6. Reduce i?. 1 to its lowest terms. 6 3 7. Reduce J^^- to its lowest terms. 8. Reduce 119. to its lowest terms. 8 9. Reduce iii to its lowest terras. 4 9 2 10. Reduce 15?- to its lowest terms. 11, Reduce -1^- to its lowest terms. * As a guide to the studem to find suitable divisors for these reduclionSjIet him observe, 1st. That any number ending with an even number or a cipher, can be divided by -2. 2d. Any number ending virith 5 or 0. is divisible by 5. 3J, If tiie right hand place of any number be 0. the whole is div;s'l>le by 10; if there be two ciphers, it is divisible by 100; if three ciphers, by lOCO. and so on. which is only cutting ofl" tho?e ciphers. 4th. If the two right hand figures of any number be divisible liy 4, the whole is divisible by 4: and if the three right hand figures be divisible by 8, the whole is divisible by 8. and so on. 5th. If the sum of the dig ts in any number be divisible by 3 or by 9, the whole is divisible by 3 or by 9. 6th If the ri?ht hand digit be even, and the sum of all the d.g;is be divisi- ble by 6, then the whole is divisible by 6. 7th. A number is divisible by 11, when the sum of the 1st. 3d. 5ih. kc. or all the odd places, is equal to' the sum of the 2d, 4th, 6th, &c., or of all the even places of digits. Sih. If a number cannot be divided by some cpiantity less than the square root of the same, that number is a prime, or cannot be divided by any number whatever. , „ ^ ^ ■ , 9th. All prim-.' numbers, except 2 and 5, have either 1. 3. /. or 9. in the Dlace of units; and all other numbers 're composite, or can be divided. Ans i. Ans i Ans. .5, 6* Ans. 2 J ^ Ans. ^ o' Ans. h Ans.). 'J ^ i' Ans. ^%_ r FRACTIONS. 77 I 12. Reduce 3.2 i P. to its lowest tcriii:^. ,-l//.v. J,. tj 4 8 II - 13. Reduce J.JJ'J'J^- to ils lowest leriiis. Ajis. 1. 6 7 18 5 1) « 14. Reduce -JJJ'J'jyL to its lowest terms. A7is. }. 15. Reduce _6_7_8AP_ to its lowest tciins. Ans. J_ 7 8 6 in' 16. Reduce -AJ^ to its lowest terms. 1057 Ans. 4. (AuT. c58.) We have thus far been s in their simplest forms ; but we have also pound Fractions, Mixed Numbers, and peaking ol Improper Complex ' proper fractions, Fractions, Corn- Fractions. An improper fraction has a numerator greater than its denominator, as t^^ ^^ Sec. A compound fraction is a fraction of a fraction, as ^ of f . A mixed number is a whole number and a fraction standing in one sum, as7|-, 11^, 19|, &c. A complex fraction is, where one or both of the ie7'ms of the frac- tion are fractional, as 2 71 2| 3L, 9, 51. By an improper fraction, we understand that the value of the ex- pression is more than a unit in value: thus, 1. As 3. make 1, 1 must equal 2^. Hence, we may reduce improper fractions to mixed numbers, by dividing the numerator by the denominator, and taking the remain- der for^the numerator of the proper fraction. EXAMPLES. 1. Reduce '_?-7 to its proper terms. Ans. 11_5_. 2. Reduce -i 1 1 to its proper terms. Ans. 153f .3. Reduce ^J/ to its proper terms. Ans. 2^-. 4. Reduce 1 £1 to its proper terms. Ans. 301. 5. Reduce ^_6_i to its proper terms. Ans. 56 ^!L, 6. Reduce ' |5 s to its proper terms. Ans. 54^1 . 7. Reduce '-P to its proper terms. Ans. 1|. 8. Reduce > 1." to its proper terms. Ans. 23|. 9. Reduce '^J^-? to its proper terms. An-. 41. 10. Reduce "isi to its proper terras. Ans. 430^. VULGAR FRACTIONS. 79 (AiiT. 39.) Whole numbers may be put under a fractional form, by placing unity under them. Thus, i. is manifestly 4, ^ is 9, Y is 44, &c. Now, by Article 36, the value of any fraction is not changed by dividing both numerator and denominator by the same number. In- versely, then, we shall not alter the value of any fraction by multiply- ing both its terms by the same number. Hence, we can reduce any number into halves, thirds, fourths, or any other number of equal parts, by first placing unity under it, and then multiplying the nume- rator and denominator by the parts required, thus : Reduce (5 units to fifths. First, 1 ; then multiply both terms by 5, and we have 3_o Answer. Again : Reduce 62 to fifths. The result is obviously 3_2 — and from this we may draw a rule to reduce mixed numbers to im- proper fractions. Rule. Multiply the whole number by the denominator of the fraction, and add in the numerator for a new numerator, and set the denomitiator under it. EXAMPLES. 1. Reduce 4^ to an improper fraction. Ans. 1, 2. Reduce 711 to an improper fraction. Ans. •'^.a. 3. Reduce 111 to an improper fraction. Ajis. i|. 4. Reduce 37§ to an improper fraction. Ans. "-^ . 53 5. Reduce 5i to sixteenths: thus, --X i-f = f f , ^«*- 6. Reduce 21 to sevenths. Ans. 14 7) 7 3_6 7 4 7. Reduce 12J_ to an improper fraction. An 8. Reduce 341| to an improper fraction. Ans. 9. Reduce 241 to tenths. Aiis. 2_y • 72^ 10. Reduce 24 1, to thirds. Atis. -g- 11. Reduce 67-^- to an improper fraction. Ans. 7_4_' . 12. Reduce 131:| to an improper fraction. Ans. 3|5 ^ 13. Reduce 211 to an improper fraction. Ans. 1 1^ If more examples are desired, the pupil can reverse those under Article 38. 80 ARITHMETIC. CO.MrOUND FRACTIONS, (Art. 40.) We have before dofined Conipountl Fractions to be fractions of other fractions, such as ^ of ^, £. of ^, &c. When a compound fraction is reduced to its simple value, it is evi- dent that that simple value must he less than either fraction mentioned, because it must be part of a per/. CompoHiid, in arithmetic, always means a product ; and, to reduce compound fractions to single fractions, we must multiply them toge- ther. Hmce, (he same problems may appear under multiplicaiiun of fractions and under ccmpound fraclioJis. To find the value of a comriound fraction, let us observe that ^ of -f is certainly 5 ; and we can obtain the same result by nuiltipiying l)oth numerators together for a new numerator, and the denominators for a new denominator, and then reducing down ; or we may cancel the twos in the numerator and denominator. Again : what is the value of ^ of -f of ?. ? One-half of f is certainly ^ ; then f of ?. is certainly less than 2, and a fraction is made less by increasing its denominator. If we double the denominator only, the fraction is one-half its former value ; if we increase the denominator by 3 times its former value, the frac- tion will he one-third of its former value, &c. Hence, J^^ is the value of 5 of -f of ^. From these observations we draw the following rule for the reduction of compound fractions to single ones. Rule. Reduce mixed numbers In improper fractions, and place a unit under whole members to put them in a frac- tional form. Then, mxiliiplii all the numerators together for a new numera- tor, and all the denominators for a new denominator, and reduce to Us lowest terms. But, skillful operators reduce by canceling, while performing the general operation. EXAMPLKS. 1. Reduce ^ of 'i of § lo a simple fraction. Ans. _^_. 2. Reduce -J of 1 of l*. of t to a simple fraction. Ans. 2L, 3. Reduce 3 of 1 of _?_ of ^ to its simple value. ^4^5. _s_ A. Reduce 2^ of I5 of £ of | to its simple value. Ans. 2. 5. Reduce ^ of i* of J of ll of 8 to its simple value. Ans. 6_5_ 6. Reduce ^ of ^ of J of i of A of il of 10 to its simple value. Ans. \l VULGAR FRACTIONS. 81 (AiiT. 41.) To invcstig;itc and ionn a rule to multiply a fraction by a whole jiuniber, we can take some simple fraction, as ^. and if it he miiltipliml by 2, the result must evidently be ? ; and if it be mul- tiplied by 3, the result must be | ; if by 5, the result must be s, &c. Also, take ^, and multiply it by 4 ; the result will be 1, or ^. Also, f multiplied by 2 will give i ; 2 multiplied by 3 is _^, or ■§ ; and from these observations, to multiply a fraction by a whole number, we de- duce the foilnwing RuLK. Mulfi'p/i/ the numerator by the whole number ,■ or, when you can, divide ihe denominator by the whole number. EXAMPLES, 1. Multiply ii by 5. Ans. y=2^- 2. Multiply ^ by 3. Ans. ~=^h- 3. Multiuly Li by 4, Ans. «l=3ll. 4. Multiply _!'_ by 100. Ans. 9-^=642. 5. Multiply ^1 by IS. Ans. 1\. 6. Multiply 1^3 by 19. Ans. 5^ = . 7. Multiply 1 by 24. Ans. 56. 8. Multiply 11 by 105. Ans. 85. 9. Multiply 3 by 63. Ans. 27. 10. Multiply 1 by 40. Ans. 25. 11. Multiply _"- by 11. Ans. 7. To multiply a whole number by a fraction is the same as to multi- ply a fraction by a whole number ; for, when two numbers are multi- plied tot^ether, it is indifferent which we call the n)ultiplier, or which the multiplicand. (See Art. 11.) That is, in the last example, ^- multiplied by U, is the same as U multiplied by _'_ ; and so of the other examples. (Art. 42.) If we mulliply a fi-adion by its denominator, it luill produce the iiumerator for a product. EXAMPLES. 1. Multiply 1 by 7. By the above rule, the product must be ^, or 3. . -, A 2. Multiply 11 by 19. Ans. 14. 3. Multiply 5 by 9. Ans. 5. ARITHMETIC. 4. Multiply 3i by 3. Ans. 10. 5. Multiply 7i by 4. Ans. 29. 6. Multiply 6 1 by 5. ^?is. 33. 7. Multiply 1^ by 17. Aris. 11. 8. Multiply ^^ by 29. ^ns. 19. 9. Multiply 33 by 7. Ans. 24. 10. Multiply 41.^ by 17. A7is. 79. 11. Multiply 15- by 21. Ans. 13. N. B. Let the pupil remember this article, when he comes to clearing equations of fractions in Algebra. (Akt. 43.) We have already defined Complex Fractions to be such as have fractions in the numerator or denominator, or in both, as — '-. Now, if we multiply both numerator and denominator of this fraction by 2, we shall have J , a simple fraction. But, why did we multiply by 2, in preference to any other number ? Ans. Because it was the denominator in the fractional part of the numerator. 3 94 Again : — is the same as 1, or -f. Also, — is a complex fraction, 4]^ ^ 8g and we can clear its numerator of the fraction by rauhiplying it by 3, and we can clear its denominator by multiplying it by 8. Hence, we can banish fractions from both numerators b}' multiplying by 3 and then by 8, or multiplying both numerator and denominator by 24 at once. Thus: 9-1X24=232; 8|X24=20I. Therefore, 232 is the equivalent simple fraction. It is now apparent that we can change complex fractions to simple fractions, by the following Rule. Multiply both numerator and denominator by the denomi- nators of the partial fractions, or by their product, or by their least common multiple. EXAMPLES. 2i 1. Reduce — ^ to a simple fraction. Ans. ll. 41 *8 7 5 2. Reduce ^rr to a simple fraction. Ans. 1 = 11, .0 o 5 5 VULGAR FRACTIONS. 83 3. Reduce -? to a simple fraction. Ans. 2.1. i „. ^^ „, 4| 4, Reduce - of o, of - ^ (o a simple fraction. 1 3 **3 4 3 4 A71S. 4_8^. 5. Reduce ~~ to a simiile fraction. A)is. ,"/_. 1 9 _ I y o 1 24 3^ 6. Reduce — of -- of — to a simple fraction. Ans. tl. 03. 2 2 ^ ^ 7. Reduce -^ of ^, to a simple fraction. Ans. -k. 8. Reduce ;;:rj of •§ to a simple fraction. Atis. _«_. If we divide i by 2, that is, one-half cut into 2 equal parts, each part will be i. If we divide ^ by 3, or in other words, cut ^ into 3 equal parts, each part must be i. But, we can obtain these results mechanically, by multiplying the denominator of the fraciiun by the divisor. If we were required to divide 2. into 3 equal parts, each part will be ;.. In this case, then, we can divide the fraction by dividing the numerator, because it is susceptible of being divided into the parts required. Therefore, to divide a fraction by a whole number, multiply the denominator of the fraction by the whole number, and place the numerator over the product. Or, when you can, divide the nume- rator by the whole number, and let the denominator remain unchanged. EXAMPLES. 1. Divide I by 3. Ans. i. 2. Divide 2 by 9. Atis. _2_.. 3. Divide |. by 5. Ans. ^. 4. Divide 11 by 13. Ans. J 1 9 .5. Divide _»_ by 8. Ajis. _"_. 6. Divide LL by 7. Ans. JJ^. 2 1- 14 7 8 4 ARITHMETIC. 7. Divide LI by 34. Ans. J„. 2 1-' 42 8. Divide ^1 by 15. . / Ans. ^. Tiiis is the reverse operation of Art. 41. [N. B. Let pupils omit the following Article the first time going I h rough.] .'- CONTINUED FRACTIONS. (Art. 44.) We have a clearer conception of the value of a frac- tion when its numerator is unity, than when it is in any other form. For in-stance, we have a clearer understanding of the fraction i than of -?^J-, although they differ in value but veri/ little. As the value of a fraction is not changed by dividing both nu- morator and denominator by the same number, (Art. 36,) we can always change the numerator to unity, by dividing both terms of the fraction by the numerator; but this will make the denominator a mixed number,* and the fraction a complex fraction. If we take the fraction -||^, and divide both numerator and deno- minator by 287, we have — , which shows that the value of the fraction is between \ and \, and 5 is its first approximate value. If we take -J.|j, and divide its numerator and denominator by 131, we then have ;— -— , and the original fraction becomes 1 If we continue to operate on the fraction ^J^ , until we find the last fraction with unity for a numerator, the original fraction, ||^, will take the following form, which is a continued fraction. 1 2-t-l_ 5-t-l__ 6 *That is: \n case the numerator and denominator are prime to each other, as il is supposed ihev are. If they are not, the fraction must be re- If we noglect tlie fractional paij of the 2ad denominator, ihc second apjToximatc fraction will be The first approximate value of the original fraction, 2 "t, is, as we have just observed, ^. The second apjiroxiinatt- value is — 2 I The third approximate value is 3T71 5 The fourth approximate value is 3-fI_ 2-fl__ 5-1-1 4 And the fifth and last approximate value is the fraction itself Let it be observed, that the principle here involved is all encom- passed in Article 36, and that we reiluce fractions to this shape by division ; and, of course, to reduce thorn back again, all we would have to do is to inspect the work, and take the reverse operation. For example, what simjile fraction expresses the value of the third a[)proximate value of the traction under consideration] We must commence with the last denominator, 1, and multiply the numerator and denominator of the fraction —7—: hy 5, which gives 5 1 _5_; then, our approximate fraction becomes = ?-l. 11' ' ^'^ 3_5_ 3 8* In this manner we shall find the approximate values of the fraction fnhpi 2 11 4fi 287 By inspection, we perceive that a continued fraction may be defined thus : A continued fraction is one that has a whole number and a frac- tion for it'^ denominator, which fraction has ahio a whole number and a fraction for its denominatur, aiid so on, as far as the frac- tion may extend; ai}d each fraction must have unity fur its numerator. 86 ARITHMETIC. The partial fractions which compose any continued fraction, are called hit egrut fractious, because each of their numerators must con- sist of a single integer. The integral fractions which compose the continued fractions, which we now have under inspection, are 5, 5, L, 1, 1. But, we have just seen that the approximating fractions are \, 2 n 4_6_ 28.7 By investigation, we find that the approximating fractions can be drawn from the integral fractions, by the following Rule. 1. The first approximating fraction is the same as the first integral fraction. 2. The second approximating fraction has the denominator of the second integral fraction fur its numerator, and the product of the first two integral denominators, plus 1, for its denominator. 3. The third approximating fraction may be fanned by multi- plying the terms of the second approximating fraction by the de- nominator of the third integral fraction, and to the products add the terms of the first approximating fraction. And thus, in general terms, to form any approximating fraction after the second, Multiply the terms of any approximating fraction by the deno- minator of the following integral fraction, and to the products add the corresponding terms of the preceding approximating frac- tion, and we shall have the terms of the next succeeding approxi- mating fraction. 1. Reduce I2 i_ to a continued fraction : find its integral fractions, and its approximating fractions. Ans. ^, I, \, 1, L. integral fractions. 5 ' G ' i 3^ Ll^ --^-^ -r^^i approximating fractioiis. ^ 2. Reduce the fraction _Y_ into a continued fraction, and find its integral and its approximating fractions. Ans. ^, 5, ^, 5, 1, I, integral fractions. APPLICATION. 3. The circumference of any circle is three times its dinnip*'r, plus the fraction -.yj-^JL. Reduce this fraction to a continued frac- tion, and find its first three integral fractions, and its first three ap- proximating fractions. Alls. |, _?_, 1., integral fractions. Y' rVe' TtV' approximating fractions. VULGAR FRACTIONS. 87 By putting the integral 3 to these fractions, and reducing to improper fractions, we have 2_2^ y|-, liA, as the approximating ratios between the circumference and the diameter of a circle. 4. The solar year is 5 hours 48 minutes 49 seconds above 365 da3's: wiuil part of 24 hours, is 5 hours 48 minutes and 49 seconds ? To answer this question, we llrst reduce both of these quantities to seconds: fi hours 48 minutes 49 seconds =20929 seconds; 24 hours =8(5100 seconds. Then, the proportional part that n hours 48 minutes and 49 seconds is of 24 hours is expressed by the fraction 2 3 L' n 8 6 4 00* Reduce this fraction to a continued fraction, and find its integral fractions and its approximating fractions. j„r X 1 1. 1. J_. 1. L. J_. are its integral fractions. And its first six approximating fractions are 5i 29' 33' 128' I61'2704* These fractions show that in every four years we must have one leap year, to make the sun cross the equator on the same day of the month, and this will be only an approximate correction. Seven leap years in 29 years would be better, or 8 in 33, or 31 leap years in 128 consecutive years, would be a very near correction, &c. 5. The planet Mercury performs a revolution round the sun in 87 days 23 hours and 15 minutes, nearly, or 126676 minutes. The earth revolves round the sun in 365 days 5 hours and 49 minutes, nearly, or in 525949 minutes. Hence, 126676 revolutions of the earth correspond in time to 525949 revolutions of Mercury ; for, 525949 X 1-6676 gives the same product as 126676X525949. From this, it appears that if the earth and Mercury are in any particular position in respect to longitude, as seen from the sun, they cannot both be in the same position again, at the same time, until after an elapse of 126676 years; but they can approximate to the same position at different intervals, which can be determined hy making a fraction of the numbers 126676 and 525949, thus 1-116 7^ Reduce this fraction to a continued fraction, and find '525949 . . ^ . its integral fractions and its approxnnatmg tractions. Am. ' I i L t 1 1 i. J-. -'-. 1, are the integral frac- -^4' IT' T' T' 2' 1' 1' 6» 6 0' 1' 3' " tions, and its approximate fractions are 1 n 7 13 3 3 ^6 T_9_ J5_2_0_ J}J_2jJ}__ J^JJTLPJL 4' IjI' l^y"' 51' T3T' T;i I' 328' 2159» 129808' 13 2027' 1 2 Ifi 76 52 5 i* 4 9 * The first fraction shows that 1 revolution of the earth has an ap- proximate value to 4 revolutions of Mercury. The next fraction shows that 6 revolutions of the earth, (or 6 years,) has a nearer approximate value to 25 revolutions of Mercury, and so on, as the reader can see by inspection. 88 ARITHMETIC. N. B. We are aware that ihe applicaiioii of contnuied fraciioiis does not belong to arithmetic, for it involves associations of ideas entirely too h;gh ; but we know from experience thai pupils in general will not take sufficient interest in abstract continued //actions to ui'.(h-;rstand them, unless they are convinced of their practical utility; and this is an apology lor giv- ing the mailer iubsequenl to example 2. REDUCTION OF FRACTIONS. (AnT. 45.) We have, thus far, treated fracuon.s in the abstract. We shall now begin to apply them to particular things, and change them from »>ne scale of weight or measure to another. But, we shall be best understood by EXAMPLES. 1. Reduce | hundred weight to the fraction of a pound. This is ihe same as asking the value of i of » 12 pounds, which, by Article 40, must be A)is. ^±^. 2. What is the value of | of 1 pound Troy ? that is, what is the value of I of »_2 ounces ? Ans. 7 oz. 4 dwts. From the foregoing observations we deduce the following Rule. To find the value of a fraction in parts of its integer of lower denomination. Multiply the numerator by the parts in the next inferior denom- ination, and divide the product by the denominator, and multiply the remainder, if ariy, by the parts in the next denomination, arid so on. The quotients placed in. cn-der, will express the value of the fraction. EXAMPLES. 1. What is the value of |. of an Ell English, in integers of lower order? Ans. 3 qr. 2^ na. 2. What is the value of | of an acre, in integers of lower' order? Ans. 3 R. 131 P. 3. What is the value of I of a hogshead ? Ans. 49 gals. 4. What is the value of 2 of 3 of one hour? Ans. 30 min. 5. What is the value of -?^ of a day in integers? Ans. 3 h. 12 min. 6. Reduce j of a dollar, or 100 cents, to its integer value. Ans. 12^ cts. 7. Reduce |o of a hogshead to its integer value. Ans. 50 gals. 8. Reduce ' |. of a day to its integer value. Ans. 16 h. 36 m. 55J5_ sec. 9. Reduce || of a hogshead to its proper quantity. Ans. 33 gal. 3 qt. I pt. 11. REDUCTION OF FRACTIONS. 89 10. Reduce 1^,- of a £ to its proper quantit}-. Ans. 18 s. 4 d. A fraction may be so small, that is, the denominator so large, in relation to the numerator, that we can obtain no integer of the wfe- rior decree. Observe the following EXAMPLES. 11. Reduce ----- of a hogshead to the fraction of a pint. Ans. 12. 8 S 12. Reduce - J__ of a day to the fraction of a minute. 15 8 4 •' Ans. I'L. 13. Reduce ." of an acre to the fraction of a rood. 14 4 Ans. ^1-. ^8 14. Reduce — 1 of a mile to the fraction of a rod. 10 5 Ans. _5_, 3 3 15. Reduce ^2_ of a £ to the fraction of a shilling. Atis. ^ s. 16. Reduce j^^-^ of a hundred weight to the fraction of a pound. Ans. A. 7 (Art. 46.) The subject-matter of this article is to perform the reverse operations of Art. 45 ; i. e. To find what part one quantity is of another. EXAMPLES. 1. What part of a pound is 3 shiUings and 4 pence ? 3 s. 4 d.= 40 pence; £1=20 s. =240 pence. Now 40 pence is obviously _4j)_ of a £, or 1 of a £. What part of a yard is 3 inches'! Manifestly JL=J_. From the above we draw the following Rule. Reduce the given quantity to the lowest denomination mentioned^ for the numerator ,- then reduce the integer to the same denomination, for the denominator of the required fraction. 2. What part of a yard is 3 quarters 2^ nails'? 3 quarters 2^ nails= 29 half nails; 1 yard=32 half nails. Ans. |9. 3. What part of 1 pound Troy is 7 ounces 4 penny-weights ? Ans. 3 . 4. Reduce 3 quarters 7 pounds, to the fraction of 1 hundred weight. Ans. ^«^.,.. 5. What part of 2 rods is 4 yards 1^ feet? Ans. ^^. 90 ARITHMETIC. 6. What part of 1 bushel is l!l pecks? Anf:. %. 7. Reduce l:J hundred weight 3 quarters 20 pounds to the fraction of a ton. Am. 12. 56 When the proposed quantity is not to be compared to, or measured by, an integer, ike same principle is observed. The following exam- ples will illustrate : 8. What part of 4 hundred weight 1 quarter 24 pounds, is 3 hun- dred weight 3 quarters 17 pounds 8 ounces ? Ans. g. 9. A man bought a piece of cloth containing 8 yards 3 quarters; it took 2 yards 2 quarters to make a coat ; what part of the whole piece did it take 1 Ans. ^. 10. A man has a journey to perform of 35 miles 7 furlongs ; after having traveled 15 miles 3 furlongs, what part of the journey has he performed? Ans. ill. * 2 8 i • (AuT. 47.) To reduce fractions from a lower denomination to an equivalent fraction of a higher denomination, we need only to observe the following process : 1 . V/hit part of a foot is h of an inch ? Now, to reduce inches to feet, we have only to divide by 12, and this we mu!-t do, whatever be the number of inches, or parts of an inch. Hence, we must divide 5 by 12, which, by Article 44, must be J_, Ans. 3 6 2. Reduce A of a cent to the fraction of a dollar. To reduce cents to dollars, we must divide by 100. Hence, _ j._ = _l_ of a dollar, •' 6 50120 ' the answer. The pupil will observe from this, that this fraction must be dvided at once, or in succession, by the number of units between the higher and lower denomination mentioned. In the following operations, considerable canceling can be used. EXAMPLES. 1. Reduce j of an ounce Troy, to the fraction of a pound. Ans. J_. 3 6 2. Reduce ' • of a minute to the fraction of a day. Ans. _^_. 3. Reduce ^-i_ of a pound avoirdupois, to the fraction of a ns. ?_^, 1. Ans. _3_ hundred weight. Ans. ?_^. 4. Reduce f of a nail to the fraction of an ell English. 5. Reduce _V. of a penny to the fraction of a pound. Ans. ^--. 576 VULGAR FRACTIONS. 91 6. Reduce i of a pint to the fraction of a bushel. Ans. -i-. 3 2 7. Reduce .?_ of an ounce to the fraction of a hundred weight. A)is. 9 8 se 8. Reduce 1 of an inch to the fraction of an ell English. Ans. _L. 7 5 (Art. 48.) To reduce a fraction from one denomination to an- other, on the same scale, Reduce 7 to fourths. We write I, and then multiply numerator and denominator by 4, making 2_8j ^^'hich is still 7 in value. (See Art. 39.) In the same way, let us reduce 4 to fourteenths ; or, in other words, change |. to fourteenths^. 5 6" We write '{ and multiply numerator and denominator by 14 14 14 14 14 2. How many fifths are (here in i of anything? Ans. 4|. 3. How many _L are there in J- of any number, or any thing? '"* Ans. 6f- This is, anything divided into 24 equal parts, 6| such parts is the same portion of the whole ais -|-''j.is of 1. 4. Reduce 1 to a fraction whose denominator shall be 4. 3^ Ans. p' 4 5. Reduce 11 to a fraction whose denominator shall be 20. Ans. -— f- 20 6. How many -V of a shilling are in 4 of a shilling ' 66 Alls. _T 12 7. How many pence are there in i. of a shilling 1 Ans. 6£. N. B. Observe, that examples 6 and 7 are substantially the same, except that one calls for the answer in parts of a shilling, the other calls for it in pence. (AnT. 49.) When several fractions have different denominators. 92 ARITHMETIC. it is important, many times, to bring them under one denomination, as we can neither add nor subtract them until this is done. (See Art. 5.) For example, reduce ^ and § to a common denominator, without charginj^ their values. Eighths cannot be reduced to halves in this case, but halves can be reduced to eighths, by multiplying nu- merator and denominator by 4, and then wc have ± and f , 8 being the common denominator. Thus, when the deiiominators are muliiples of each other, and the pupil has a clear understanding of the nature of a fraction, he can reduce them all to one, or a common denominator, by multiplying or dividing numerators and denominators, as judgment may dictate. EXAMPLES. 1. Reduce |, _s_, J'_, to equivalent fractions, having a common denominator. Ayis. ^s_^ _6_^ _5_, 2. Reduce 1 _?_, J'-, to their equivalents, having a common de- nominator. " Ans. _2_, _5_^ _8_. All rules for reducing fractions to a common denominator must be based on the principle that, numerators and denominators multiplied or divided by tlie same number, does not change the value of the fraction. On this principle, we may understand the following rule, which is universal in its application : Rule. Multiply each numerator irito all the denominators ex- cept its 0W71, for a new numerator. Then multiply alt the deno- minators together for a new denominator, and place it under each new 7iumerator. 1. Reduce -f, 2, and ^, to a common denominator. 2X2X4^=16 the numerator for -f. 1X3X4=12 - do. - |. 3X3X2=18 - do. - |. 3X2X4=24 the common denominator. The equivalent fractions are {1 6-_2 24— 3* 1 2-_l 24 2* 2 4 4* It is evident that the values of the fractions are not changed, be- cause both the terms of each are multiplied by the same number. 2. Reduce 1 and 1 to a common denominator. Ans. J 63 7' VULGAR FRACTIONS. 93 (AiiT. 50.) To follow the above rule in all cases might often require more niechauical labor than necessary ; and to abridge the operation we must lind, not merely the common, but tlie least com- mon denominator. Preparatory to this, we must be able to find the least commnn mxil- tiple of tw!) or more numbers ,- that is, the least number divisible bij them icUlwut remainders. RfLK. Write the numbers one after the other, and draw a line beneath them ; then, take any prime nund)er which will divide two or more of them tvithout remainder, and divide all the num- bers tiiat will so divide — ivriting the quotients beneath, and all the numbers that are not divisible by it. Find a prime number that will divide two or more numbers in this second line, and proceed as bpfore. Continue the operation tmtil there are no two numbers left bavins; a common divisor; then, multiply all the divisors and re- maining numhers together, and their product will be the least com- mon multiple sought. 1. Let it be required to find the least common multiple of 12, 15, 7, 18, 3, 5, and 35. 7 5 3 2 7X5X3X3X2X2=1260. First, dividing by the prime number 7, we find that it divides two of the given numbers, 7 and 35 — the rest being written in the line below. We take 5 for the next divisor, which di'^des 15 and 5. Continuing the operation in the same manner, we divide successively by 3 and 2, when the division can be carried no further. Then, mul- tiplying all the divisors together, and that product by the undivided prime numbers left, and the result in this case is 1260. It is evident that this must be the least common multiple, because it contains 07ily the prime factors necessary to make up the given numbers. The same must be true of any other numbers. 2. Find the least number that is divisible by 9, 12, 16, 24, 36, without remainders. Ans. 144. 12, 15, 7, 18, 3, 5, 35, 12, 15, 1, 18, 3, 5, 5, 12, 3, 1, 18, 3, 1, 1, 4, 1, I, 6, 1 1, 1, 2, 1, 1, 3, 1, 1, 1. 94 ARlTHMliTlC. N. B, In the opeiHtion, 9 anri 12 may I'e leO f^nt, as any num- ber divislibe by 36 will be divisible by 9 and 12, 3. Find the least number divisible by each of the nine digits A71S. 2520. 4. Find the least number divisible by 75, 50, 15, 20, 30, and 45. Ans. 900. (Aut. 51.) We are now prepared to give the following rule for finding the least common denominator to any set or group of fractions. Rule. Find the least common multiple of all the denominators. This will he the common denominator. For the numerators, divide the common denominator by each particular denominator, and mul- tiply the quotient by its numerator. EXAMPLES. 1. Reduce ^, 4, y-, and ^-^ to the least common denominator. 7 2 2, 7, 16, 21, 2, 1, 16, 3. 1, 1, 8, 3. 7X2X8X3=336, least common denominator, or denominator to all the new fractions. To obtain the new numerators, divide this by the former dtnominators, and multiply the quotient by the former numerators, thus: 336X1 — =168= 1st numerator. 2^L>lf=192=2d numerator. 7 336X3 „ — — — =63=3d numerator. 16 336X3 — _ - — =32=4th numerator. The new fractions equivalent to the given fractions are l^lt i-^, J5 3_ Ji2_ 3 36» 3 3 6 2. Reduce _"_. 1. 1. and i, to their least common denominator. An^. AHl 231 3.12 1 5 1 616' 616' 6Ifi» 6 Tfi' 3. Reduce _2_, ^^^ :|7^ and J'-^ to their least common denomi- nator. " Ans. J^_ JJ_ Lll 8 . 150' I50» 150' 150 VULGAR FRACTIONS. UT) ^4. Keduce -^ .»_^ ^, and 6, to their least coihuidi) denoiniriator. Ans. -s_fi_, JJ, 1-L'l. LJJ?. •J32'252'25i;» 252 5. Reduce S^, 2^, and If, to their least common denominator. AflS. 4J l_8 IJ. A ^, 8 » 8 ' S 4 2-^ 6. Reduce ^ of ^, 7 andji to their least common denominator. s ^ AnS. -8^ 4 80 4 5 . 2 4' 2 4 » 2 4 7. Reduce -- of -^, -^ of -^ and 7, to their least common deno- minator. Ans.^-?^J 111 2_2_o_5 3Ts ' 3 1 5' 315' ADDITION OF FRACTIONS. (Art. 52.) We cannot add unlike things together, (Art. .5,) therefore, betbre fractions can be add(ul, we must be positive that they not only refer to the same integer, (lielong to the same scale of mea- sure.) but have the same denomination of that scale. For illustra- tion, we cannot immedintely add together f of a foot and -J of an inch, for tlie s.uiie reason that we cannot put feet and inches into the same .sum. Equally impossible is it to add fourths and thirds toge- ther. Hence, all the difiiculty a pupil will meet with will be in mak- ing the preparations to add, and not in adding. When all the preparations are made, the fractions are added by adding together the numerators, and setting the common denominator under the sum ; for, the sum of ^, £, and g, is ccrtaiiily il. Take the second example of the last article (51), and require the in of _?_^ |, ^, and i- The equivalent fractions having a common denominator, we see by "erring back to article 51, are A?l. 'l'±l., 252 \_b_i^, ° (>16'016'616»G16 Their sum is 504-|-23I-|-252-4- 154=1 141. Am. »-ij'_i 6 16' From the foregoing we deduce the following general Rule. Reduce ihe fractions, if necessary, to the same standard or integer of measure ,- compound fractions to single ones, and ail to a common denominator,- then, add the numerators, and place their sum over the common denominator. When several fractions have denominators that are multiples of each other, as i, i, |, &c., we can reduce them to a common denomi- nator without any formality of rule, by simply multiplying the nume- rators and denominators of those fractions having the smaller denomi- nators, by such numbers as will bring the denominators alike. 'J'hus, in the above, ^=i> 4=|, and | stands: and their sum is -1=1^. 96 ~ ARITHMETIC. In the same manner we find the sum of the fractions ^1, |, | and ^1, to be Il^Ve* A similar operation will give the sum of the following fractions : L-J-l-Ul-i--'^— It is evident that these denominators measure 24; 2 T^ 6 1^ n n^ 1 2 that is, all of them will divide 24 ; hence, we can change all the frac- tions to twenty-fourths, by mere inspection. Thus, 1 = 12 i =_4 3 = _9_ _"_ = !,£. Sum, 3 9._1|. 8 24' 12 24 24 " When we have mixed numbers, add the whole numbers separately, and then add the fractions. The two sums put together will be the sum required. EXAMPLE. Add 3i, Ih 21, ry^, 9tV, together. Integers, 3-l-7-}-2-i-74-9 =29. Fractions, « |+_n_-l-_«_-l--3_+/-=||=|. ' Whole sum, 298. EXAMPLES FOR PRACTICE. 1. Add I and 2. Ans. 3 5. 2. Add I, I ^ and 5^ together. .4ns. li.||. 3. Add I, i, 2^ and ^ of |, together. Ans. \^^-. 4. Add together ^^^^J^-^- Ans. U t p. 5. Add I of i of |, to 6| of i, and f of je , together. ylns. 4JL. I 8 6. Add I of a rod to | of a foot. Ans. 13^ feet. 7. Add i of a mile, ■§ of a furlong, and |- of a rod together. Ans. 307|. rods. 8. Add ^- of 3^, _?_. of 2^, -?_ of U, _i_. of 2|, and !)_ of 3^, together. ^W5. I. [This last example is very simple and brief.] 9. What is the sum of ^ of a pound and |^ of a shilling ? ^7W. 'i|5=13s. lOd. 2|q. 10. What is the sum of § of a yard and ■§ of a quarter ? Ans. I_i_ yards. 11. What is the sum of 2. of a ton, added to ^ of a hundred 3 / weight? A'^is. 123 cwt. SUBTRACTION OF FRACTIONS. 9' 12. What is the sum of g of a day added to ^ of an hour ! Ana. 9t, hours. 13. What is the sum of f oi a pound and ^ of a shilling] Ans. 3s. 2d. 14. What is the sum of 1 of a week, | of a day, and i of an hour? Ans. 1 d. 22 h. 15 m. SUBTRACTION OF VULGAR FRACTIONS. (Art. 53.) We would remind the pupil that, in addition, we took the sum of the numerators, after the fractions were reduced to a com- mon denominator. Hence, the difference of the two fractions must 1)3 found by taking the difference of their numerators, when the deno- minators are ahke. For example, the difference between _"_ and _?_, must be -? _ i and the difference between f and f niusl be f, 6lc. These observations must give us the followmg RuLK. Prepare ihe fractions as for addition, and place the dif- ference of the numerators over ihe common denominator, fir the dif- ference tf the fractions. EXAMPLES. 1. Find the difference of t and J- . Ans. s 12 I -i 2. From # take 1. Ans. _«_. * 7 £ 8 3. From 6| yards take 3| yards. Rules would reduce these numbers to improper fractions, and then to a conjmon denominator, thus: ^J and 3J*, difference -J=z'2,^. But, a little tact, which should always be cultivated, will do it more elegantly, thus: 6|=5'Jj and 34=31; hence, 2^ is their dilier- ence. In like manner perform the two following : 4. From 9L take Q^_. Ans. 2J_. 5 10 10 5. From I9i vards take 12_?_ yards. Am. 6L?.. 6. What is the difference between f of b\ and | of 4i. Ans. 1-2. ■) 7. What is the difference betv/een ^ of a rod and | of a foot ? Ans. 1^ feet. 8. From ^ of a yard take f of a quarter. Ans. ^ quarter. 9. From i. of a pound take -f of ^ of a shilling. " Ans. £i_i=10s. 7d. Uq. 3 6 ^ ^ 10. From f of a yard take J of a quarter. Ans. 'J'=l qr. 3 na. 98 ARITHMETIC. 11. From 7 ells English take 4J yards. Ans. 32 ells English. 12. From 1 of a pound sterling take | of a penny, / * Ans. 2s. iLld. 13. From 1 of a rod take -f of a foot. Aiis. 3J nr 10^ feet. 14. From 1 of an ounce take -| of a pennyweight. A7if!. ''_5j» dwt., or 16LL dwt. 2 3 ' 2 S MULTIPLICATION OF FRACTIONS. (Aht. 54.) Multiplication is the same in its nature, whatever may be the value of the numbers multiplied together. When we consider two terms or factors to be multiplied together, a multiplicand and a mulliplier, the multiplicand must be taken as many times as there are units in the multiplier. When there is not a unit in the multiplier, then we are to multiply by a fraction, and it is taking the multij)licand part of one time, and, of course, the product will be less than the multiplicand. For example : Let it be required to multiply 2. by 2. Here 1 is to be considered the multiplier, which is twice i. Now, we must, obviously, take ^^ 4, of 1 time, — that is, divide it by 7 ; which is, by Article 44, J-. But, we want |, twice as much as 1 : hence, JL. must be the required product. And this we should have obtained by the following Rule. To multiply one fraction by another. Multiply the nu- merators together for the numerator of the required fraction, and the denominators together for the denominator ; always canceling, when possible. N. B. Mixed numbers must be py-eviously reduced to improper fractions. Another explanation : 1. Multiply I by |. Ans. /^==y\. 3X2 6 Here '-— = — • But, the multiplier is only the l part of 2 ; con- 4 4 * sequently, i must be diminished corre-spondently, by multiplying its denominator by 5. 2. Multiply 2^ by I of I of 8. 5X3X2_X8^X2_e^^ 2X4X5X1 1 MULTIPLICATION OF FUACTIONS. 09 An.s. 4^. f by 7i by ^^„ by 7. Atis. 23. , and 4_''_. ^n.5. 2J_. J 1. Multiply 5 by -f of ^. ./1/J5. 1. 2. Multiply J*-, by ^, and that product by 7^-. 3. Required the product of 21 by 4. Required the product of 1 5. Multiply together 5, f, 1 of li, and 41. yl/?.s. sj' =71. G. Multiply fi of 3 times _9_ of 5 times ^ of ^ of i, by 1 of i of A of J . 7lrt5. g^. 7. What will 8^ pounds of tea cost as 1^^ dollars per pound 1 A71S. 1011 dollars. 1 6 8. What will 4| cords of wood cost, at 3| dollars per cord ? Ans. 1713 dollar?. 1 6 9. If a horseman travel at the rate of 7^ miles an hour, for 6_"_ hours, how far will he have gone? Ans. 51 -U miles. 10. What is the cost of 9^ yards of linen, at $lf per yard ? Ans. $12.15. ^ 6 4 DIVISION OF FRACTIONS. (AuT. .5.5.) The essential nature of division is the same, whether the dividend and divisor are whole numbers or fractions. It is, sim- ply, finding how many times, or what part of a time, one num- ber is contained in another. For example: We may demand that 6 shall be divided by j>, and an inattentive pupil might suppose that we required tlie half of 6 ; but this is not true. We demand how many ti'iies ^ is contained in 6: or, we might say. Divide 6 into equal parts, and have each part equal to {j ; how many parts will there be ] Ans. 12. Divide 6 by ^. Am. 18. Divide 6 by J_. Ans. 60. Divide 6 by |. Ans. 42. Divide 6 by 2. Ans. As 1 is contained in 6 42 times, 2 will be con- •'7 7 7 tained 21 times. That is. We multiply the dividend by the denomi- nator of the divisor, and divide the product by the numerator. When the dividend is a fraction, the result may be obtained by the following Rule. To divide by a fraction, invert the divisor, and proceed as in muUiplicutidn. N. B. When the divisor is a compound fraction^ invert every ierrii ,• and, in all cases, caticel as much as possible. 100 ARITHMETIC. EXAMPLES. 3 21,3 Form, — ^— Canceled #,3 9. ^??s. 48. u47lS. 117. -4/25 49. ^ns .99. I. Form -^ 5 4. 4. 4. 5. '3: 1. Divide 21 by |. 2. Divide 18 by f. 3. Divide 63 by _7_. 4. Divide 42 by ^. 5. Divide 66 by |. 6. Divide f of ± by i of I Canceled ■ ^' ^' — ; therefore, 4 is the answer required. ^. A- 1- ^• 7. Divide 4 of _«_ of ^, by i of 6 of -"_. yl"5. 4. 8. Divide ]^^ of I of 1.^ of 1-f of |8 of i, by ^ of i of _P_ of 4- Ans. m=l2J-. 4 1 3 4 7 o 9. Divide 4^ by i of 64. Ans. _'/-,.. 10. Divide 6| by | of 42. A«5. -jP_. .11. Divide f of I by 4 of 6^. Ans. ^^-. (Art. 56.) Fractions must refer to the same scale of weight or measure, before we can divide one by the other. For instance, we cannot divide the fraction of a gallon by the fraction of a pint, or by the fraction of a gill, before we reduce one to the denomination of the other, for the same reason that we cannot add and subtract unlike quantities, (Art. 5.) EXAMPLES. 1. How many times is •§ of a pint contained in 1 of a gallon 1 Ans. 6^. 2. How many times can a vessel holding _P_. of a quart, be tilled from 5 of a barrel, containing 31^ gallons ? Ans. 4G|. 3. How many rods are there in 60^ yards ? Ans. 1 1. * 4. How many times is | of an inch contained in 1 of a yard ? Ans. 3i2. 5. How many times is 1 of a rod contained in ^ of a foot ? A71S. J-. » 9 PRACTICAL APPLICATION OF FRACTIONS. 101 PRACTICAL APPLICATION OF FRACTIOxNS. 1. What will 51 yards of calico cost, at 31^ cents per yard ? Alt.'. '^pl.CA-{- 2. What will S^ yards of linen cost, at G2^ cents per yard ? 3. What will 5-} yards of linen cost, at Sl:^- cents per yard ? An.v. S4.67-I- 4. Bought a yard of cloth for ^ of a dollar ; what would be the cost of 8 yards, at the same rate ? Ans. $6^. 5. If I pay I of a dollar for a gallon of oil, what will I85 gallons cost? ' Ans.^i^^. 6. What would Jl of an acre of land cost, if ^ of an acre cost 5^27. Ans. $48. 7. Bought f of a fifteen-acre lot, and sold | of what I pur- chased; how much did I sell? Ans. 4^ acres. 8. What would 395 pounds of sugar cost, at ? of ^ of a dollar per pound? " Ans. $52^. 9. Add i of a pound sterling to ^ of ^ of a shilling. Ans. 2s. 10|d. 10. Add I of a mile, ^ of a furlong, and J5_ of a rod together. Ans. 233^ roJs. IL Add 1 of a hogshead to ^ of a gallon. Ans. 54-^- gallons. 12. What is the value of » of a day? Aiis. 10 h. 17^ m. 13. What is the value of 1 of a dollar? Ans. 421 cts. 14. Reduce | of |. of a pound, avoirdupois, to integers. Ans. 4 oz. 11|3 dr. 15. From J- of a ton take f of a hundred weight. A71S. -\ cwt. 16. If ^ of a dollar pay for 3| pounds of sugar, how many cents is it per pound ? Ans. 10. 17. If $20J pay for 16^ barrels of apples, what is the cost per barrel ? Ans. $1 ,26, nearly. 18. If ^ of 2 of a farm cost 1200 dollars, what would the whole cost 1 Ans. §7200. 19. If 6 pounds of tea cost 9^ dollars, what is it per pound ? Ans. Sl|. 20. If 5^ yards of cotton cloth cost § of a dollar, how many cents is it per yard ? Ans. 15_5_. 21. If ^ of a dollar pay for 1| yards of cloth, what is the price per ell English. Ans. 79_.fi_. 22. If a piece of cloth measuring 13f yards, cost 27^ dollars, what is the value of 1 yard 1 Ans. |2_2_. 102 arithmp:tic. 23. If 7 horses consume 2| tons of hay, how much does each con- sume ? Ans. 11. 24. What part of a rod is 2^ yards 1 A?is. _5_. 25. Find the difference between 3 of an ell English, and t of 3 feet? Ans. IJ_. 5 6 Questions. How do you judge of the value of a fraction ? What numbers do you compare in making up your judgment? ]f you double a denominator, what effect does it have upon the fraction ? If you double a numerator, what effect does it have? If you double both numerator and denominator, what effect ? If you add the same number to both numerator and denominator of a fraction, does it change its value? How do you reduce complex fractions to simple ones ] DECIMAL FRACTIONSr (Art. 57.) The common or vulgar division of things into halves, quarters, thirds, &c., &c., so convenient and proper in the every-day little concerns of business life, becomes troublesome and perplexing when we have a variety of these different denominations to add or subtract in large mathematical calculations; and, to surmount this difficulty, we have a more artificial division of things into tenths, those parts again into tenths, and again, if need be, these svibdivisions into tenths, &c., Sec. ; thus having a decreasing order of fractions on the same graded scale as natural numbers, ten of one.order making one of another ; and, of course, we may call them decimals', from deci- mils, the Latin word meaning tenths. From this it is evident tliat, if we divide a tenth into ten equal subdivisions, one of them will be one- hundredth of the unit, &c., &c. ; hence, decimal fractions can have no other denominators than 10, 100, 1000, &c., &c. This being systematized and properly understood, the denominators need not be written. If the fraction is tenths, one place from the unit wdl ex- press it, with a point between ; if hundreds, or two orders from the unit, two places of figures must be taken : thus, _i_ is expressed .05, _^_-_ thus, .005, always as majiy places as the understood denomi- naior contains ciphers. Thus, 7_s'_ is written in decimals, .... 7.5. 4tVo' 4.24. I^Vt/WV' 141-1356. DECIMAL FRACTIONS. 108 Ciphers written niter a decimal neither increase nor decrease it, for this does not change the place of the figures. 'I'hus, 2^'^ is 2.6, and 2.60000 is the same value — the 6 still being in the same orc/e?- of numbers; but, ciphers on the other side, as 2.06, changes the orc?er, and diminishes the value ten-fold for every remove. The following shows the scale : ■±3 « -r: P J3 '^ C llllllllJllia 333333 3, 333333 Express the following in figures. • 1. Sixty -six and seven-tenths. Ans. 66.7. 2. One and thirty-five-hundredths. Ank: 1.35. 3. Eighty-one and 1 ten-thousandth. ^ws. 81.0001. 4. One hundred and 67 ten-thousandths. Ans. 100 0067. 5. Three and three-hundredihs. Ans. .S.03. 6. Seventy-five and 75 ten-thousandths. Atis. 7f».C075. Let it be observed, that these fractions vary in value on the same scale as whole numbers ; and the denominations of Federal Money are nothing more than whole numbers and decimals, the (lollars being units, and the cents, mills, &c., being decimals of a dollar, as men- tioned in Article 8. To familiarize decimals to Federal Money, let the pupil make the following reductions : 1. Reduce §41.7 dimes and 6 mills, to mills. ^1;?.*. 4I70G. 2. Reduce 31806 mills to dollars, cents, and mills. Am. 31.806. 3. Reduce $10, 3 dimes 4 cents and 9 mills to mills. A)is. 10349. 4. Reduce 12349 mills to dollars, cents and mills. J»5. $12,349. 5. Reduce $25 to cents Ans. 2500. ADDITION OF DECIMALS. (Art. 58.) We again call to mind the fact mentioned in Article 5, that only like things can be added together. In whole numbers, 104 ARITHMETIC. units can only be added to units, tens to tens, &c. So in decimals : tenths can only be added to tenths, &c. Hence, we have the follow- ing rule for addition in decimals: Rule. Set down the numbers to be added so that tenths shall fall under tenths, hundredths under hundredths, 6(c. Tliis will brins; all the decimal points directly under each other ,- add up as in wh(jle numbers, and place a separatrix between the units and decimal. We shall give but very few examples under this rule, as the opera- tion, (except the case in placing the decimal points under each other,) is the same as in addition of whole numbers. EXAMPLES. Add 37.03, 621.57, .521, 20.007. (2) Operation. Operation. 37.03 .199 621.57 2.7569 .521 ,25 20.007 .654 Sum, 679.128 Sum, 3.8599 3. What is the sum of two-tenths, two-hundredths, and two-thou- sandlhs ? Ans. .222. 4. What is the sum of 14, and 16 ten-lhousandths? Ans. 14.0016. 5. What is the sum of twenty-six and twenty-six hundredths, sev- en-tenths, and six and seventy-three hundredths, four and four thou- sandths ] Ans. 37.694. 6. What is the sum of 9 dollars 3 mills, 14 dollars 3 dimes 9 cents 1 mill, 104 dollars 9 dimes 9 cents 9 mills, 999 dollars 9 dimes 1 mill, 4 mills, 6 mills, and I mill 1 ylns. §1 1"28..^05. 7. What is the sum of 4 dollars 21 cents, 87^ cents, 3 dollars 6^ cents, 2 dollars 2 cents, 5 dollars 372 cents, and 37 dollars 7 cents 1 Ans. $52.16i. SUBTRACTION OF DECIMALS. ( Aut. 59.) From the very nature of these numbers, as previously explained, we must have the following Rule. Place the numbers as in addition of decimals, subtract as in whole numbers, and place the decimal point in the remainder, under the decimal points above. DECIMAL FRACTIONS. 105 EXAMPLES. 1. From 91.73 take 2.138. 91.73 (2) 2.73 2,133 1.9185 /l/i5. 89.592 Ajis. .8115 3. Find the (Utrerence between 714 and .916. Ans. 713.0S4. 4. From .145 take .09GS4. Ans. .04816. 5. How much greater is 2 than ,298? Ans. 1.702. 6. What is the ditierence between 75 dollars and 75 cents ? 7. From 21.004 take 75 hundredths. Ans. 20.254. 8. From 260.4709 take 154.0578. yln.s6,4131. 9. From 10.0302 take 2 ten-thousandths. Ans. 10.03. 10. From 2.01 take 99 hundredths. Ans. 1.02. MULTIPLICATION OF DECIMALS. (.Art. 60.) Vie propose now to investigate a rule for the multi- plication of decimals; and as these numbers vary as simple num- bers, ten of one order making one of a superior order, the actual mul- tiplication of the figures must be the same as taught under simple multiplication : it only remains to point out the value of the product. Let us multiply .3 by .5. To understand the operation, make vul- gar fractions of them, and we have J^- to multiply by ^-. The product (Art, 54) is JJL ; or, by the definition of decimals, .15. Again: Multiply .oVby .13, or _^^_ by _y_. Product, __s_2__, or, by the definition of decimals, .0052. Psow, we perceive that every place in a decimal has a cipher cor- responding in a denominator understood ; and the multiplication of these denominators make as many [)laces as there are ciphers (Art. 15) ; that is, as many as there are places of decimals in both the fac- tors. Hence, we have the following RuLF.. Multiply as in simple niimhers, and point off in the pro- duct, from the right hand, as many figures fur decimals as there are decimal places in both factors ; and if there be not so many in the product, supply the deficiency by prefixing ciphers. Multiply ,02345 by .00163. .02345 .00163 7035 14070 23 i 5 .0000382235 Product. 106 ARITHMETIC. 2. Multiply 54.25 by 2.2S02. Ans. 123.70536. 3. Multiply 15.278 by .7854. Ans. 12, iienilv. 4. Multiply 79.317 by 23.15, Ajis. 1836.88305. 5. Multiply 350 by .7853. Ans. 274.855. fi. Multiply 20 by .55. Ans. \l. 7. Multiply one-tenth by one-tenth. A7is. ,01. 8. Multiply 25 by twenty-live hundredths, Ajis. 6.25. 9. At 4^ mills apiece, what will 400 quills cost ? Aiis. ^1.80. To multiply decimals by 10, 100, 1000, Sfc, remove the decimal paint as many places to ike right as there are ciphers in the multi- plier, agreeably to Article 13. Removing the decimal point one fig- ure to the right increases every figure ten-fold, &c. 10. Multiply 4.56 by 10. Ans. 45.6. 11. Multiply §1.75 by 100. Ans. $175. 12. Multiply .006 by 1000. Afis. 6. 13. A benevolent person, whose income was $6000, gave .12 of it for charitable purposes ; what did he give away ? Ans. $720. 14. The capital stock of a bank was | of a million of dollars, and _3_ of it was owned equally by 4 individuals ; how much was owned by each ? Ans. $22500. DIVISION OF DECIMALS. (AiiT. 61.) Division being the reverse of multiplication, and it having been shown, in multiplication of decimals, that the product of any two factors must contain as many decimal places as the num- ber of decimals in both factors : now, the divisor and quotient, in divi- sion, may be considered as factors of the dividend ; hence, the number of decimal places in the quotient must be equal to the difference of the number of places in the divisor, and the number made use of in the dividend. If the dividend really have no decimals, make a decimal point at the right of the unit, and fill up the blank decimal places with ciphers, as many as you wish. In dividing, the decimal places may run out ; we may then annex ciphers and count them as decimals. If the dividend has decimals, but not so many as the divisor, fill up blank places, as before, which will not affect the value of the decimal, (Art. 57). From the above explanations, the reason of the following rule must be evident: Rule. Divide as in whole numbers, and poiyit off from the right of the quotient as many places for decimals as the decimal places in the dividend exceed those in the divisor. DECIMAL FRACTIONS. 107 1 1. H 2de( more made two 2 3. 4. 5. fi. 7. EXAMPLES. Divide 42.42 by 2.113. Operation. 2.113)42.4200(20.07 42.26 ICOOO 14791 ^ere were, originally, oration we used three s with ciphers. This taken from it, leaves Quo^.O.llI. Quot. 11 1. Quot. 5.4232. Quot. 54.232. Quot. 16.278. 30 by .03. ere we rest, and count off the quotient. T :imal places in the dividend, and in the op( ; that is, filled up three blank decimal place } five, and three, the number in the divisor decimal places in the quotient. Divide 2.3421 by 21.1. Divide 2.3421 by .211. Divide .8297592 by .153. Divide 8.297592 by .153. Divide 12 by .7854. Divide 3 by 3 ; divide 3 by .3 ; 3 by .03 ; (Art. 62.) The preceding rule for division of decimals is as clear and as explicit as any mere ruJe can be : but, so careless are pupils in general, about the decimal point, that little or no reliance can be placed on the value of their quotients, until they are taught to use iheir judgments in each and every case, independent of any rule. To call into exercise this individual reliance, is the object of the fol- lowing remarks and explanations. To divide — to cut into parts — will not, at all times, give a clear understanding of division, and confusion frequently arises from taking this view of the subject; we better consider it as one number mea- suring another. For example : How often will .5 of a foot measure 12 feet? In other words, divide 12 by .5, or divide 12 by ^. Here, if the student should imagine that 12 must be cut into parts, he would make a great error. He must divide 120 tenths into parts ; in this cai^e, into 5 parts, because the 5 is .5 : or, he may consider that ^ of a font may be laid down in 12 feet ; that is, measure 12 feet 24 times. Or, he may reduce the 12 feet to half feet, and then divide by 1. In fill cases, the divisor and dividend must be of the same denomination, before the division can be effected. But, in decimals, those rcductitms are made so easily that a thoughtless operator rarely perceives them ; hence the difficulty in ascertaining the value of the quotient. We now give a few examples, for the purpose of teaching the pupil how to use his judgment. He will then have learned a rule more valuable than all others. 108 ARITHMETIC. EXAMPLES. DiviJe 15..34 by 2.7. Here, we consider the whole number, 1.5, is to be divided by less than 3 : the quotient must, therefore, be a Httle over 5. One figure, then, in the quotient, will be whole numbers, the rest decimals. Divide 15.34 by .27. Here we perceive that 15 is to be divided, or rather measured, by less than | of 1 ; therefore, the quotient must be more than 3 times 15. Or, we may multiply both dividend and di- visor by 100, which will not aflect the quotient, and then we shall have 1534 to be divided by 27. Now, no one can mistake how much of the quotient will be whole numbers : the rest, of course, decimals. Divide 45.30 by .015. Conceive both numbers to be multiplied by 1000 ; then the requirement will be to divide 45300 by 15, a common example in whole numbers. By attention to this operation, the student will have no difficulty in any case where the divisor is less than the dividend. Here is one of the most difficult cases : Divide .003753 by 625.5. In all such examples as this, we insist upon the formality of placing a cipher in the dividend, to represent tlie place of whole numbers, thus : 625.5)0.0037530( V/e now consider whether the whole number in the divisor will be contained in the whole number in the dividend, and we find it will not : we, therefore, write a cipher in the quotient, to represent the place of whole numbers, and make the decimal on the right, thus : 0. We now consider that 625 will not go in the ID'S, nor in the lOO's^ nor in the 3, nor in the 37, nor in the 375, but it will go in the 3753^ We must make a trial at every step, that is, every time we take in vieiv another place ; and we must take but one at a time. In this case, then, we shall have 0.000006, the quotient. Divide 3 by 30. 30 will not go in 3 ; we, therefore, write for place of whole numbers, and then say, 30 in 30 tenths, 1 tenth times, or 0.1. Divide .55 by 11. 11)0.55(0.05. 1 1 in 0, no times ; 1 1 in 5 tenths, no times ; 1 1 in 55 hundredths, 5 hundredths times. It will be observed that we make the decimal point in the quotient as soon as we ascertain it; not wait, and DIVISION OF DKCIMALS. 109 then find where it should be, by counting, &c., — ;i rule against which we have notliing to say; but good jutig- ment, at ready command, is far superior to any rule that can be formed. EXAMPLES* 1. Divide 9 by 450. ^ns. 0,02. 2. Divide 2,39015 by ,007. J9ns. 341,45. 3. Divide 100 by ,25. ^ns. 400,00. 4. If 350 pounds of beef cost $12,25, what is the cost of one pound ? *^ns. ,035. 5. At $5,75 per yard, how much cloth can be pur- chased with $19,40625? ^ns. 3,375 yards. ^- 6. At 7 per cent., how much capital must be invested to yield 602 dollars ? ^ns. $8600. 7. If a contribution, amounting to $36,72, be made by a congregation consisting of 918 persons, how much is it a-piece? ^ns. ,04, or 4 cents. 8. If 275 lemons cost $2,475, how much is it a-piece? ^ns. 9 mills. 9. A benevolent individual gave away $600 per annum to charitable objects, which was ,12 of his income ; what was his income ? (Art. 63.) By paying some litde attention to the rela- tion of numlDcrs, we may abbreviate certain divisions, in a similar manner as we abbreviated multiplication, m Art. 21. To divide by ,25 is the same as to multiply by 4. " " by ,5 is the same as to multiply by 2. " " by ,75 is the same as to multiply by 4, and divide by 3. To divide by ,125 is the same as to multiply by 8. " " by ,333|- is the same as to multiply by 3. " '« by ,666| is the same as to multiply by 3, and divide by 2, Slc. &c., for any aliquot part of unity. The same is true of aliquot parts of 10, 100, 1000, &c. EXAMPLES. 1. Divide 6 by ,25. ^ns. 24. 2. Divide 6 by 25. - Jns. ,24. 3. Divide 15 by 16|,=^ of 100. ^ns. ,9. 110 ARITHMETIC. 4. Divide 15 by ,16|. ^ns. 90. 5. Divide 4,27 by ,33^. .^ns. 12,81. REDUCTIOIN OF DECIMALS. -.-_ (Art. 64.) To reduce a vulgar fraction to its equiva- lent decimal : the value of any fraction is found by di- viding the numerator by the denominator; thus, |=2. But in a proper fraction, we cannot divide the numerator without first reducing it. Annexing one cipher, makes it tenths ; two ciphers, hundredths ; and so on. The quo- tient, therefore, will be decimal parts. Thus : reduce | to a decimal. 8)1,000 ,125 We may take this view of the case : Multiply both numerator and denominator, by 10, 100, 1000, &c. ; which will not change the value of the fraction, (Art. 35.) We then have |^^^. Now divide both numerator and denominator by 8, and we have yVVo' which is a deci- mal fraction, by the definition of decimals. Hence, whichever view we take, we have the following Rule. Place a decimal point at the right of the nu- merator, annex ciphers, and divide by the denominator. Compound fractions must first be reduced to simple fractions. EXAMPLES. 1. Reduce \, \, and |, to equivalent decimals. Jins. ,25, ,5, ,75. 2. What decimal is equivalent to |? Ans. ,625. 3. What decimal is equivalent to | of | ? Ans. ,4. 4. Reduce |f to a decimal. Ans. ,9375. 5. Reduce y^'jij to a decimal. Ans. ,0008. 6. Reduce jf to a decimal. Ans. ,7058 + There are many vulgar fractions that cannot be exactly expressed in decimals. The following are some of them : 2 1 2 4. A _1_ _2_ Stjf, REDUCTION OF DECIMALS. HI Reduce I to a decimal. Ans. ,3333, - <^ MISCELLANEOUS EXAMPLES. 1. What will 20 cords of wood cost, if 48 cords are worth 120 dollars? ./Ins. $50. 2. If 20 cords are worth 50 dollars, what will 48 cords cost? .^ns. $120. 2X4 :: 690 Jins. Ans. Ans. $9,20 A. 130 ARITHMETIC. 3. If 120 dollars will purchase 48 cords of wood, how iPiany cords can be bough. t for 50 dollars ? A)Vi. 20. 4. Thirty-six gallons of wine were purchased for 108 dollars, what should be given for 4 gallons ? Ans. $12. 5. If 7 men can do a certain piece of work in 12 days, how long will it take 15 men to do one-half of it? (See Art. 80.) Ans. 2i days. 6. If 8 yards of cloth cost 3^ dollars, how many yards can be bought for 50 dollars ? Ans, 1 14| yd. 7. A garrison has provision for 8 months, at the rate of 15 ounces per day ; what must be each man's allow- ance, that the same provision may last them 12 months ? Ans. 10 ounces. By Art. 83, this problem is solved thus : oz. oz. provis. pi'ovis. 8X15 : 12X[] :: 1 : 1. Hence, 12 , _ ^ =Ans. Keep the same Art. in mind in solving the two follow- ing: 8. When a quarter of wheat affords 60 ten-penny loaves, how many eight-penny loaves may be made from the same ? Ans. 75. 9. If 10 dollars' worth of provision serve 7 men 4 days, how many days will the same provision serve 9 men ? Ans. 3^ days. IQ. If 15 degrees of longitude cause a difference in time of 1 hour, what will be the hour at Washington, when it is 12 o'clock at a place situated 36° 45' east of it? Ans. 9 o'clock 33 min. 11. If a man's yearfy income b# $2000, and his aver- age expenditures be S25,87^ per week, how much can he lay up in 6 years, including one leap-year ? Ans. ^4057,621. 12. If 17 men do a piece of work in 20 days, in what time will 20 men do double the work ? Ans. 34 days. 13. If a staff 3 feet 8 inches long, cast a shadow 1 foot 6 iuciies, what is the height of a steeple that casts a shad- ow 75 feet at the same time ? Ans. 183'^. 14.^4f I of an ell English cost \ of a pound, what will 12| yards cost? Ans. £5 lis. l\ d. PROPORTION. 131 15.il If 12!, hundred weight of iron cost $42] , what will 48;'5- liundred weight cost? ./Ins, $163,50. 16. What quantity of Hning, f yard wide, will it re- quire to line 9|. yards of clotli, 1-^ yard wide ? .r]ns. 15^ yards. 17. If 12 gallons cost $30, what will 63 gallons cost ? JIns. $157,50. 18. How many yards of clolli, 3 quarters wide, are equal to 30 yards 5^ quarters wide ? .^ns. 50 yards. lO.'How'many yards of paper, | of a yard wide, will be sufficient to "hang a room 20 yards square, and 3^ yards high ? ./^ns. 400 yards. 20. If 28 dollars are paid for 15 gallons of wine, what is the price per pint ? *^ns. 23} cents. 21. If 240 bushels of wheat are purchased at the rate of $22V for 18 bushels, and sold at the rate of $33| for 22 V bushels, what is the profit of the whole ? Ms. 60 dollars. 22. If $100 gain $7 interest in a year, what will $49,- 75 gain in the same time ? ^n-s. $3,48 'j. 23. If a hogshead of brandy cost ^61 6 16 shiUings, what Mdll 12 gallons cost ? ^ns. £3 4 s. 24. If 27 yards of Irish linen cost £5 12 shillings 6 pence,. how many ells English can be bought for £100 ? Ms. 384. 25. If 300 cwt. be carried 660 miles, for 4 dollars, how many hundred can be carried 60 miles for the same mo- ney? ^ns. 3300. i^26. What quantity of water added to 31-^- gallons of whisky, which cost $13,50, would enable the purchaser to sell it for 40 cents per gallon, at a profit of 10 cents a gallon on his purchase? Ms. 10^^ gallons. 27. If it require 90 yards of carpeting, J wide, to car- pet a floor, how many yards, 11 wide, would be suffi- cient ? *^^i^' 60 yards. 28. If 9 1 yards of linen cost 2 pounds 12 shillings, what will 32 1' yards cost in dollars, at 4 shillings 6 pence, each? .^775. $382. 29. At $2,75 for 14 pounds of sugar, what would be the price of I hundred weight? Ms. $22. / 30. If A can Aow ^, B i, and C j of an acre of grass I ; — 132 ARITHMETIC. in an hour, in how many hours can ihey together mow 'S\ acres ? ^ns. 6 h. 30 m. 30;, sec. J ^ 3 Ip* IX A^, and B together can do a piece of work in 7 "X. 1 9^ysv^t;id;^ alone in 12 days, in how many days can A alone do f of it? | ^9ns. 1^ days. 32. If 5 hundred weight 3 quarters 14 ppunds of su- gar cost 6 pounds 1 shilling 8 pence, how many dollars, at 6 shillings each, will 35 hundred weight 28 pounds cost? ^.; c^n*. $121f. N. B. See example 2, Art.^TQ. 33. A merchant bought of a farmer 120 bushels of wheat at 75 cents per bushel, and sold it at 20 per cent, advanced price ; what did he receive for the whole, and how much did he gain ? Statement, 100 : 120 : : 75 : to the merchant's price, 90 cents ; whole gain, $18. .\, | 34. A merchant bought sugar at $4,75 per 100 pounds; how much shall he sell it per pound to gain 25 'per cent.? ^<^ns. 6 cents, very nearly. 35. ^Bought tea at 62^ cents per pound, but by a fall -ra the market, I am willing to sell it at 10 per cent, loss ; 'what shall be the price of it ? Jins. 56^ cents. N. B. The three preceding problems could properly be put under the technical head of loss and gain ; but it is as propp7' that they should be under proportion. 36. A pole, whose height is 25 feet, at noon casts a shadow to the distance of 33 feet 10 inches : what is the breadth of a river which runs due East, at the bottom of a tower 250 feet high, whose shadow extends just to the opposite edge of the water ? ^^ns. 338 ft. 4 in. 37. A plane of a certain extent having supplied a body of 3000 horses with forage for 18 days ; how long would it have supplied 2000 horses? .^liis. 27 days. 38. If a carriage- wheel in turning twice round, advance 33 feet 10 inches ; how far would it go in turning round 63360 times ? .^ns. 203 miles. 39. Sound flies at the rate of 1142 feet in 1 second of time: I heard the report of a gun 1 minute and 3 seconds after I saw the flash ; how far distant was it ? PROPORTION. 133 40. If a carter haul 100 bushels of coal at. every 3 loads, how many days will it require for him to load a boat with 3600 busiiels, suppose he hauls 9 loads a day ? ^ns. 12 days. 41. If the moon move at the average, rate of 13° 10' 35" in one day, how lonjr will it require to perform a re- volution ? ' Ans. 27 d. 7 h. 43 m. nearly. 42. The mean motion of the moon being-, as stated in the last problem, 13° 10' 35" per day, the mean apparent motion of the sun in the same time 59' 8"33, wliat time will be required for the moon to gain a revolution on the sun ? Ans. 29 d. 12 h. 44 m. 3 s. Questions. What is meant by comparison of numbers? Ans. An examination of their relative magnitudes or values. When such magnitude is expressed, what is the ex- pression called ? Ans. Proportion, or ratio. It is called ratio, when one number is expressed by unity. Is the ratio of two numbers the same as the quotient resulting from the division of one of them by the other ? What name is given to the first, and what to the second term of a couplet ? When two pairs of numbers have the same ratio, what do they constitute? What name is given to the two outer terms, and what to the two middle terms of a proportion ? What relation is there between the product of the means, and the product of the extremes of a proportion ? Why is the product of the means equal to the product of the extremes ? AVhat rule is founded on this equality ? Explain the common method of stating in the Single Rule of Three. How do v.e proceed after a question is stated ? Why must the two like terms be brought to the same denomination ? When we have the 1st, 2d, and 4th terms of a propor- tion, how do we find the third ? When a factor of any one term is wanting, how is it found ? M 134 ARITHMETIC. COMPOUND PROPORTION: OR, THE DOUBLE RULE OF THREE. (Art. 82.) The following rule is common to all modern authors, though they may make slight variations in ex- pressing it. We give it in the words of Mr. G. "Wilson, v/ith an example and its accompanied explanation, as ex- pressed in great clearness and brevity. Compound Proportion is compounded of two or more ranks of proportionals, five, seven, nine, &;c., terms be- ing given to find a sixth, eighth, &c. Rule. Work by two or more statements in Simple Proportion ; or, set that term, which is like the term sought, in the third place, and consider each pair of similar terms and this third one, as the terms of a state- ment in Simple Proportion, and set them severally, in the first and second places, agreeably to the directions under that rule. TVhen the question is thus stated, reduce the similar terms to the like denominations, and then multiply all the terms in the second and third places together, arid divide the product by the product of those in the first place; the quotient will be the answer, or term sought. The method of statement will best be illustrated by an example. 1. If 8 men can build a wall 20 feet long, 6 feet high, and 4 feet thick, in i2 days, in what time v/ill 24 men build one 200 feet long, 8 feet high, and 6 feet thick ? Here the answer sought men 24 : 8"^ , is days. We, therefore, length, 20 : 200 ! ^^ place 12 days for the third ^ • ' ■ term, and comparing the number of men, it is evi- dent that 24 men will re- quire less time to do the same piece of work than 8 men. We therefore place the less of the two numbers last. men 24 . 8^ length, 20 : 200 ! height, 6 : thickness, 4 : 6J COMPOUND PROPORTION. 135 We next compare the length of the two walls, and see that one 200 leet long will require more clays than one 20 feet long, and place the longest last. For the same reason, we arrange the heights of the two walls in the same order; and so also of the thickness. The con- tinued product of all the middle terms and the third term, divided by the product of all the first terms, gives the an- swer 90 days. But the labor of multiplication (as in simple propor- tion) may be shortened by reducing any of the first terms, and any of the other terms proportionally by division. Or we may draw a perpendicular line, and cancel as in Art. 24; the full multiplications and divisions should never be accomplished, unless the numbers are prime to each other. The preceding method is very good, as a 7nechanicol contrivance^ but, as a philosophical expression, it will not bear criticism. We prefer the following, by reason of its greater simplicity and more extensive application. (Art. 83.) It is an axiom in philosophy, that equal causes produce equal effects; and that effects are always proportionate to their causes. Now, causes and effects that admit of computation, that is, involve the idea of quantity, may be represented by numbers, which will have the same relation to each other as the things they represent. Keeping these premises in view, then, we have an uni- versal rule, applicable to all cases which can arise un- der Proportion, simple or compound, direct or inverse, namely : Rule. As any given cause is to its effect, so is any required cause (of the same kind) to its effect; or, so is another given cause, of the same kind, to its required effect. The only difficulty the pupil can experience in this system of proportion, is readily to determine what is cause, and what is effect. But this difilculty is soon overcome, when we consider that all action, of whatso- ever nature, must be cause — and wdiatever is accomplish- ed by that action, or follows such action, must be eifect. 136 ARITHMETIC. EXAMPLES. 1. If 16 horses, in 50 days, consume 128 bushels of oats, how many bushels will 5 horses consume in 90 days ? Ans. TZ. Here it is evident, that the consumption of oats spoken of, in both the supposition and demand, are the true ef- fects ; and the action of the horses, multiplied by the days, must express the amount of cause. We shall, therefore, state it thus : Cause. Effect. Cause. Effect. 16 : 128 :: 5 : n 50 90 We write the factors, one under another, as above ; their multiplication is understood, but rarely or never ac- tually accomplished. The second effect is an unknown term, or answer, required — a bracket, or blank, or point, is left to represent it. When found, the four terms above would be 2. perfect geometrical proportion, and the pro- duct of the extremes equal to the product of the means. In this example, the product of the means is perfect ; which product, divided by the factors in the extremes, will give what is wanting in the extremes, namely — the answer. Therefore, agreeably to our mode of performing mul- tiplication and division, we draw a line thus, and cancel down : 16 50 128 5 90 2. If $480, in 30 months, produce $84 interest, what capital, in 15 months, will produce $21 ? Now, capital will not produce interest without time; and, whatever be the rate per cent., the same capital in a double time will produce a double interest. Therefore, Cause. Effect. Cause. Effect. 480 : 84 : : [ ] ; 21 30 15 COMPOUND PROPORTION. 137 Here one element of the second co.use is wanting; that is, tlie answer to the question. In this case, the extremes ar& complete ; we will there- fore, divide the product of the extremes by the factors in the mean, and tlie quotient will give the definite factor ^ or answer, namely — $240. 3. If 7 men, in 12 days, dig a ditch 60 feet long, 8 feet wide, and 6 feet deep, in how many days can 21 men dig a ditch 80 teet long, 3 feet wide, and 8 feet deep ? It is almost too plain for comment, that 7 men, multi- plied by 12 days, must be the first cause, and the con- tents of the ditch they dig, the effect. Therefore, Cause. Effect. Cause. Effect. 7 : 60 : : 21 : 80 12 8 [] 3 6 8 Here, as in the preceding example, one of the elements of the second cause is wanting ; or, rather say a factor in the means of a perfect proportion, and can be found as above. Jins. 2| days. 4. If 6 men build a wall in 12 days, how long will it require 20 men to build it? Ans. 3| days. (Art. 84.) Questions of this kind are usually classed under the single rule of three inverse ; they do, in fact, however, belong to compound proportion: but, as one of the terms is the same in the supposition as in the de- mand, it may be omitted. That term, in the present ex- ample, is, one wall. If we make the number different in the two brandies of the question, or connect any con- ditions with it, such as lengths, breadths, &c., it at once falls under compound proportion of necessity, and may be stated thus : Cause. Effect. Cause. Effect. 6:1 : : 20 1 12 [] 5. If 4 men, in 2| days, mow 6| acres of grass, by working 8{ hours a "day, how many acres will 15 men mow in 3| days, by working 9 hours a day? Ans. 40 yy acres. ITT- 138 ARITHMETIC. Cause. Eject. Cause. Effect. 4 : 6f :: 15 : [] ^ 3J 81 9 Let the pupil observe, that when a correct statement is made, there will be the same number of elements, or factors, under the same letters, as in the above example. Under each cause, we have men, days, and hours, to be multiplied together. When there are fractions in any of the terms, their denominators are to be placed over the line from where the term belongs; mixed numbers being previously reduced to improper fractions. 6. If 12 ounces of wool make H yards of cloth, |- of a yard wide, how many yards, l\ wide, will 16 pounds of wool make ? Ans. 22 1 yards. With this example, some might hesitate as to arranging it under cause and effect, as the actors, those who made the cloth, whether many or few, have nothing to do with the question. But we take the phrase of the example, and say, The wool makes the cloth. Cause. Effect. Cause. Effect. 12 : H :: 16> [] i 16^ • H 7. If the transportation of 124 hundred weight, 206 miles, cost $25,75, how far, at the same rate, may 3 tons and 3 quarters be carried for $243 ? Ans. 402f miles. In this example, it is indifferent which we take for the cause, and which for the effect. We may say, that the money, 825,75, is the cause of having the weight car- ried ; or, we may say, that carrying the weight is the cause of purchasing the money. There are many ques- tions where it is indifferent which we take for cause, and which for eflect. The above example may be stated thus : Cause. Effect. : : 243 : 60| cwt. [] Cause. Eff'ect. 60J : 243 206' ^ [] Cause. Effect. 25^- : 124 cwt. 206 miles Or thus : Cause. Effect. ' 12± : 25| COMPOUND PROPORTION. 139 Or thus : Cause. 12i 206 Cause. : 60?- [] Or thus : Effect. 243 Effect. : 251 Effect. Effect. 251 : 243 Cause. Cause. : 60| : 121 [] 206 These changes show, conclusively, that this method of statement is strictly scientific and philosophical ; and, in all these different arrangements of the terms, the scnne terms are multiplied together. The most that can be said for the common mode of statement, in the Double Rule of Three, is, that ihe pro- ducts, when the terms are midtiplied out, are propor- tional. But the first and second terms, taken as a whole, express no particular idea or thing ; whereas, in this mode of statement, the thing — the philosophical idea — is the only sure guide. Nor is this all ; it is very extensive, and easy in its application ; it will cover every case that can arise under interest — to find time, rate per cent., &c., and thus do away, or suspend, five or six special rules, which encumber every arithmetic. We give a few ex- amples, to apply this rule. 8. What is the interest of 240 dollars for 3-2 years, at 6 per cent.? Cause. Effect. Cause. Effect. 100 : 6 :: 240 : [] 1 3t To obtain the answer from this statement, we perceive that we must multiply the means together — i. e. 240 X 6, the rate, and that by the 3i years, the time — and divide by 100; and this is the common ride. 9. The interest of a certain sum of money, at 6 per cent., for 15 months, was 60 dollars ; what was the sum ? ^ns. $800. Cause. Effect, Cause. Effect. 100 : 6 :: [ ] : 60 12 15 140 ARITHMETIC. 10. If 800 dollars, in 15 months, should gain 60 dol- lars, what would be the rate per cent.? Ans. 6. Cause. Effect. Cause. Effect. 800 : 60 : : 100 :[ ] 15 12 11. Eight hundred dollars was put out at interest, at 6 per cent., and the interest received was 60 dollars 4 how long was it out ? Ans. 15 months. Cause. Effect. Cause. Effect. 100 : 6 :: 800 : 60 12 [] 12. If 12 men, working 9 hours a day, for 15| days, were able to execute f of a job, how many men may be vnthdravm, and the residue be finished in 15 days more, if the laborers are employed only 7 hours a day ? Ans. 4 men. 13. The amount of a note, on interest for 2 years and 6 months, at 6 per cent., is 690 dollars ; required the principal. Ans. S600. 14. What is the interest of 1248 dollars, for 16 days? Ans. $3,28. Cause. Effect. Cause. Effect. 100 : 6 :; 1248 : [] 12? , 16 30^ days. This can be canceled down, and made very brief. 15. What is the interest of 1200 dollars, for 15 days, at 6 per cent.? Ans. $3,00. 16. What is the interest for 160 dollars, for 36 days, at 7 per cent.? Stated by cause and effect. Ans. $1,12. Cause. Effect. Cause. Effect. 100 : 7 :: 160 ; [] 12 1.2 17. The interest of a certain sum, for 36 days, is $1,12 — the rate per cent, is 7 ; what is the sum ? Ans. $160, 18. The interest of 160 dollars for 36 days, is $1,12 ; what was the rate per cent.? Ans. 7. COMPOUND PROPORTION. 141 19. The interest of 160 dollars, at 7 per cent., was $1,12; what was the tune? JIns. 36 days. 20. In what time will any sum double itself at 6 per cent.? At any per cent.? JIns. At 6 per cent., in 16| years; at any per cent., divide 100 by the per cent. 21. If 2^ yards of cloth, 1| wide, cost 3 dollars 37^ cents, how much will 36", yards cost, 1 i yards wide ? ^Ans. $52,79. 22. If 1 men spend f of f of f of Vi of £30, in -fy of ^- of 14 of y of 9 days, how many dollars, at 6 shil- lings each, will 21 men spend in | of \^ of ^ of yS of 45 days? Ans. $630. 23. I lend a friend 200 dollars for 6 months ; how long ought he to lend me 1000 dollars, to requite the fa- vor — allowing 30 days to a month? Ans. 36 days. 24. If 1000 men, besieged in a town, with provisions for 5 weeks, allowing each man 16 ounces per day, be reinforced with 500 men more — and supposing that they cannot be relieved until the end of eight weeks — how many ounces a day must each man have, that the provis- ions may last them that time?^ Ans.^S\ ounces. 25. If a foot-man, in 12^days, traveling ^lours a day, perform a journey of 240'miles, in how many days will he perform one of 720^Tiiles, if he travel 8 hours a day? Ans. '21 days. ^^ 26. If 20 men, in 12 days, working 5 hours a day, can perform a piece of work, how many hours a day must 15 men work, in order to perform 3^- times as much work in 30 days 1 Ans. 8-^ hours. 27. In what time will $627,50, loaned at 7 per cent., pro^^\yx\.^^ months, up to the end of the year, aiicl subtract the amount for the amount of the principal sum. Then we cast interest on the remainder, to the day of setllement. By Rule 1, no interest would be paid until the day of setdement; hence, with heavy sums and long trjnsac- tions, or in any case where annual interest is expected, Rule 1 is not* proper; but where a note or bond does not run two years, and several payments are made witli- in a few months of each other, Rule 1 corresponds, both in letter and spirit, to the principles of simple interest, opposed to usury. A correct understanding of this mat- ter among the people, may prevent considerable litigation and some injustice/-' 4. $2500.' One year from date, I promise to pay James Vance, or order, two thousand tive hundred dollars, with interest, for value received. George Kidd. Bosloih Jan'y 1, 1836. As a personal favor to James Vance, George Kidd paid on this note, Mav 1, 1836, ^400. Julv 1, 1836, 300. No'vember 1, 1836, 600. February 1, 1837, 800. George Kidd not being able to pay more at this time, and James Vance being pressed for money, disposed of the note at under value, to a note-shaver. Kidd took up the note Julv 1, 1837; what was then due? Ans. Bv Rule 1, S535. By Rule 2, 541,77. Difference, 6,77. A difference of feeling now arose, as to which rule should decide the balance ; the note-shaver, like Shylock, * On making inquiry of a lawyer, of very considerable practice, how he made up balances on notes, mortgages, &c., cm which several payments had bten made, he replied— When my cUent is plaintiff, I go from payment to payment: when defendant, and is to pay the balance, I reckon on the whole time, and then on the payments up to the day of settlement ; and, if the opposing lawyer makes no ob- jections, all is well ; if he does, I must conform to law. SIMPLE INTEREST. 165 contended for the law, the time being more than a year. 'J'he other contended that he paid part of the note before it was due, to accommodate tlie former holder, and the present holder bonirht it under vahie ; and more- over, according to the principles of equation of payments, no partial compound interest could be exacted. Which rule should decide the balance? The technicalities of the law favor Rule 2d ; the true spirit of the law would es- timate by Rule 1st. 5. For value received, I promise to pay Joseph Linn, or order, two hundred and seventeen dollars and tifty cents, in four months, with interest afterwards. G. Davis. Hartford, July 11, 1831. On tins note were the three following endorsements : 1831. Nov. 16, $93. 18.32. Feb. 12, 50. 1832. Aug. 2, 67,50. 1832, Oct. 4, the note was taken up; how much was due upon it? ^n.5. $11,05. This being in Connecticut, must be computed by the Connecticut rule. 6. A note of hand, dated New York, April 4, 1838, was given for the payment of six hundred dollars, on which there were endorsements as follows: — July 10, 1838, $84,64; November 22, 1838, $10,00; April 30, 1839, $14; December 5, 1839, $309. What was the balance due on taking up the note, April 5, 1840 ? Ans. $251,03. Neiv York, July 10, 1830. 7. Four years from date, we jointly and severally pro- mise, for value received, to pay to the order of George R. Guernsey, eight hundred and sixty-four dollars, with interest. Robert C. Duncan. David Johnston. On this note are endorsements as follows: April 6, 1831, $34. June 21, 1832, 300. February 26, 1833, 180. January 1, 1834, 40. What was the balance due at the maturity of the note ? 166 ARITHMETIC. COMPOUND INTEREST. (Art. 96.) When interest is payable at definite and stated periods, such as rents and special loans, for a deti- niie time, the time comes, and neither principal nor in- terest are paid — both due. A new obligation throws them into one sum, forming a new principal, the interest being on interest. Another period elapses; nothing is paid, and a like obligation takes place, interest again be- ing on interest, which is called compound interest. This explanation must give us the following Rule. Compute the interest up to the time that it be- came payable, and add it to the principal; then cast the interest on that amount for the next period, and add it to its principal, and so on. The first principal subtracted from the last amount, will give the compound interest for the whole time. Example. What is the compound interest of $250 for 3 years, at 7 per cent.? The compound interest of $250, is 250 times greater than the compound interest for $1,00. We therefore compute on 1 dollar. Principal and interest, 1st year, 1,07 Multiply by 1+07, or, 1,07 7,49 1,07 Principal and interest, 2 years, 1,1449 Multiply by 1,07 80143 1,1449 Amount of $1, for 3 years, 1,225043 Drop $l,and we have ,225043 for the compound interest of 1 dollar; which, multiplied by 250, gives $56,36, Ans. The above operation might be expressed thus: (1,07=^— 1)X 250 = 56,26. COMPOUND INTEREST. 167 2. Find the amount of 1 dollar every year, for 4 years, at compound interest at 6 per cent. Amount at the end of the 1st year, $1,0G 1,00 Interest, 2d year, ,00 3G Principal, 1,00 Amount at the end of 2d year, 1,12 30 1,06 Interest, 3d year, ,0674 16 Principal, 1,12 36 Amount at the end of 4th year, 1,19 10 16 1,06 Interest, 4th year, ,07 14 60 96 Principal, 1,10 10 16 Amount at the end of 4th year, • • • 1,26 24 769 (Art. 97.) In this manner, we can compute the amount of one dollar at any per cent., for any number of years, and it is evident that two dollars will amount to twice as much as one dollar; three dollars, three times as much ; ten dollars, ten times as much, &c. Hence, if we have a table with the amount of one dollar, at several rates, and for a number of years, we can take such amount from the table, and multiply it by the number of dollars in question, and the product will be the amount of that number of dollars, for the time required. TABLE 1, Showing flip amovjif of One Dollar for one month and quarters, at the several rates mentioned. 1 month. 1 quarter. 2 quarters 3 quarters 4 qr. 1 yr. 4 per ci'iii.4-i- per cent.; 5 per cent, jo^ per cent. 6percen 1,003333 1,009853 1,019804 1,029852 1,04 1,003750 1,0041G7 1,004583 1,005 1,011065 1,012272 1,013475 1,014074 1,022252 1,024694 1,027132 1,029563 1,033563 1,037270 1,040973,1,044671 1,045 11,05 1,055 |l,06 168 ARITHMETIC. TABLE 2,*' Showing the amount of One Dollar, from one to twen- ty years. r 4 percent. I 4^ per cenl. 5 per cent. SJ per cent. G per 1,0400000 1,0816000 1,1248640 1,1698585 1,2166529 1,2653190 1,3159317 1,3685690 1,4233118 1,4802442 1,5394540 1,6010322 1,6650735 1,7316764 1,8009435 1,8729812 1,9479005 2,0258161 2,1068491 2,1911231 1,0450000 1,0920250 1,1411661 1,1925186 1,2461819 1,3022601 1,3608618 1,4221006 1,4860951 1,5529694 1,6228530 1,6958814 1,7721961 1,8519449 1,9352824 2,0223701 2,1133768 2,2084787 2,3078603 2,4117140 1,0500000 1,1025000 1,1576250 1,2155062 1,2762815 1 1,3400956 1,4071004 1,4774554 1,5513282 ; 1,6238946 1,7103393 '1,7958563 i 1,8856491 :i,9799316 2,0789281 |2,1828745 1 2,2920 183 ,2,4066192 2,5269502 2,6532977 1,0550000 1,1130250 1,1742413 1,2388246 1,3069598 1,3788426 1,4546789 1,5346862 1,6190939 1,7081440 1,8020919 1,9012069 2,0057732 2,1160907 2,2324756 2,3552617 2,4848011 2,6214652 2,7656458 2,9177563 1,0600000 1,1123600 1,1910160 1,2624769 1 1,3382256 1,4185191 1,5036302 11,5938480 1,6894789 11,7908476 1 1,8982985 2,0121964 2,1329282 1 2,2609039 '2,3965581 2,5403517 12,6927727 '2,8543391 3,0255995 |3,2071355 * By inspection of Table 2, it will be seen that any sum doubles itself at 4 per cent., compound interest, in less than 18 years; at 4^ per cent., in less than 16; at 5 per cent., in less than 15 ; and at 6 per cent., in less than 12 years. The amount, at every rate, in- creases faster and faster, as the time increases. In 19 years, at 6 per cent., the amount is more than 3 times the original amount ; and in 40 years, more than ten times that sum. These facts show that it would work much injustice and ruin, to allow compound interest. Though in times of prosperity, and in schemes of speculation, mo- ney may be worth 6, and even a greater, per cent.; yet, in the sober realities of life, in unsettled estates in law, men in a state of bank- ruptcy, or other contingency, which must leave debts in an unsettled condition, ruin must follow, if compound interest were allowed by law. Capital would swallow up competency, the widow and the orphan would lose their inheritance, and the unfortunate could never recover from misfortune. There is much small logic abroad, concerning the abstract justice of compound interest ; but this sub- ject has engaged the attention of the most gifted minds, in all ages, and in every civilized country ; and the result has invariably been a condemnation of eorapound interest COMPOUND INTEREST. 109 3. Find the compound interest for 475 dollars, for 5 years, at 5 per cent. From the table, opposite 5 years, and under 5 per cent., we find 1,34009 For the amount of $1. We multiply by 475 6,70045 9,38003 5,30036 Amount, . . . 036,54275 Principal, • . 475 ^ns. 161,54 + N. B. When the interest alone is required, as in the preceding example, neglect one unit in the table, and ihe product will be the interest at once. 4. Wliat will 786 dollars amount to, in 3 years and a quarter, at 6 per cent.? ^^ns. $949,87 -{- l,1910ft)=amount of 1 dol. for 3 years. l,014674=am't of 1 dol. for 3 mos. or 1 qr. 4764064 8337112 7146096 4764064 1191016 1191016 1 ,208492968784=the amount of $1 for the given time. 78.^=: the given sum. 7250957812704 9607943750272 8459450781488 949,875-}- =the amount for the time required. 5. What is the compound interest of 629 dollars, for 7 years, at 6 per cent.? ^^ns. $316,78 -f 6. What will be the compound interest on a bond, for I $750, for 4| years, at 5^ per cent.? Ans. $217,18 + — 170 ARITHMETIC. 7. What is the compound interest of 3200 dollars, for 8 years, at 5} per cent.? 8. What is the compound interest of 720 dollars, for 7 years, at 6 per cent.? Ans. $362,61 -\- 9. A broker loans money at the rate of 6 per cent, per annum, but renews quarterly ; how much interest does he receive per annum, on 100 dollars ? Principal, 100 Interest, 1st quarter, 1,50 Principal, 2d quarter, 101,50 Rate per quarter, ,015 50750 1015 Interest, 2d quarter, 1,52250 Principal, 101,50 Principal, 3d quarter, 103,0225 ,015 5151125 1930225 Interest, 3d quarter, 1,5453375 103,0225 Principal, 3d quarter, 104,56783 ,015 52283915 10456783 Interest, 4th quarter, 1,56851745 Principal, 104,56783 106,13634 100 Ans. $6,136 -f DISCOUNT AND BANKING. 171 On 1000 dollars, the interest would be 61 dollars and 30 cents. It will be observed, that this problem does not correspond, in number, to Table 2 ; nor should it, though the rate per annum is tbe same; the imit of time, in that table is one year, and the unit of time in this example, is one quarter. DISCOUNT AND BANKING. (Art. 08.) Discount, — counting back, — a deduction from an account, applicable to demands due at a future time not drawing interest, and applicable to notes on which the interest is paid in advance ; the drawer re- ceiving a sum in hand, which, at the specified rate of in- terest, will amount to the face of the note in the speci- (lecl time. The problem, then, of discount, is, from the raff, lime and amount, to find the principal. Interest is proportion (Art. 89) ; hence discount is proportion also. A double sum, to run the same time and at the same rate, will require a double discount, &c. &c. Now, if we assume a principal, and compute the amount on it for the given rate and time, that amount will be to its principal, as the given amount to its required principal. If we take unity for the assumed principal, and compute the amount corresponding to the given rate and time giv- en in any problem, that amount will be the 1st term of a proportion, one (or unity) the 2nd term, and the given sum the ,3rd term. But, as the 2nd term is one, we find the 4th term by dividing the 3rd term by the 1st. Therefore, to obtain the present worth of a future pay- ment, we have the following Rule. Divide the given sum by the amount of one dollar, or one pound, for the given rate and time. The difference between the given sum and present worth, is the discount. EXAMPLES. ]. What is the present luorth and discount on $150, due 9 months hence, discounting at the rate of 6 percent.? 172 ARITH3IETIC. The amount of 1 dollar for 9 months, at 6 per cent., is 1,045; hence, as 1,045 : 1 : : 150 : present worth. By rule : 1,045)150,000(143,53 -j- 1045 4550 4180 Given sum, . Present value Discount, . . . 3700 3135 . 143,53=Prin. . $6,47 5650 5225 3250 3135 115 2. A holds a note of 375 dollars, due in 90 days, but is much in want of ready money, which the debtor agrees to pay, provided A will allow discount at 7 per cent.; what would be the discount? Amount of $1, 3 months, at 7 per cent., is 1,0175. By rule, 1,0175)375,0000(368,55 + 30525 69750 61050 87000 81400 Given sum, • • • 375= Amount. Present worth, 368,55 =Prin. Discount, . $6.45, Jns. 50000 50875 51250 50875 3750 DISCOUNT AND EANKIXG. 173 Let the pupils notice, that the sums we call present values, in the precedinof examples, are principals, which, put at interest for their respective rates and times, would give the amounts stated in the questions. 3. A person pays a debt of 394 dollars, 1 year and 8 months before it is due, discounting at per cent.; what must he pay? Ans. $358,18 -h 4. What is the present worth of 775 dollars 50 cents, due in 4 years, at 5 per cent, per annum? Jln.'i. t|;564G,25. 5. What is the present worth of 580 dollars, due in 8 months, at 6 per cent, per annum? Jhi^. $557,69 -\- 6. What is the present worth of 954 dollars, due in 3 years, at 41, per cent, per annum .' .uUh. $840,528 + 7. What is the discount of 205 dollars, due in 15 months, at 7 per cent, per annum ? .^ns. $16,495 + 8. Bought goods amounting to 775 dollars, at 9 months' credit; how much ready money must be paid, allowing a discount of 5 per cent, per annum ? Ans. $746,987. 9. B owes A to the value of 1005 dollars, to pay as fol- lows: viz. 475 dollars in 10 months, and the remainder in 15 months; what is the present wortli, allovv^ing dis- count at 6 per cent, per annum ? Ans. $945,404. 10. What is the difference between the interest of 2260 dollars, at 6 per cent, per annum, for 5 years, and the discount of the same sum, for the same time and rate per cent.? Ans. $156,462 + (Art. 99.) Discount and Bank interest ought to be the same, and are the same in the state of New York; but elsewhere, even in England, as far as the author's in- formation extends, bank interest is simple interest, on the face of a note paid in advance ; not interest on the present worth — not interest on what the drawer actually receives — but interest on what he promises to pay at a specified time. For example, A presents his note at a bank, properly endorsed to run a year, the legal interest of the state being 6 per cent.; the bank gives him $94, reserving 6 dollars for discoxmt. Now, 94 dollars, put out at interest for a year, at 6 per cent., will not amount to 100 dollars; therefore, the rate per cent, that a bank _ 174 ARITHMETIC. draws interest, is more than the nominal rate — in fact, more than lawful interest.- Banks rarely discount paper that has more than 4 months to run ; they always prefer short periods, for two reasons. One is, that it is difficult to look far into futurity, and decide on future circumstan- ces ; and the other is!^ that short intervals, and advance payments of interest, give them all the advantages of compound interest. Bank notes — or rather, notes dis- counted by a bank — run three days longer than tJie time specilied, called three days of grace; but the interest is computed for the three days, and the note need not be taken up until the last day. From the preceding explanations, it is evident that Bank interest must be compu ^d as simple interest, on the face of the note adding three days to llie time — except in New York, where bank interest is discount, as computed by the rule under Art. 98. EXAMPLES. 1 . A note for 350 dollars, for 90 days, was discounted at bank ; what was the discount ? Operation. Rule, under Art. 94, . . • 20 /t0(^ 1 3^^0 7 2 ^0 1 ^^ 31 4,0)217 .fins,' • .$5,42',. 2. What is the bank interest on a note of 135 dollars, payable 90 days after date? Ans. $2,091 -f 3. What is"^the bank interest on a note of 1850 dol- lars, payable 90 days after date? Ans. $28,671. 4. What is the bank interest on a note of 475 dollars, payable 30 days after date ? Ans. 82,61. 5. AVhat will be the proceeds of a note of 1370 dol- lars, payable 30 days after date ? Ans. 1362,46|. * Yet, the supreme courts ha '3 decided, that this mode of cal- culating discount is not usury Banks are, therefore, authorized by judicial authority to discount at a higher rate than that establish- ed by law. We know not on what principles this decision has been made. DISCvOUNT AND BANKING. 175 6. What will be the proceeds of a note of 880 dollars, payable 90 days after date ? ^2ns. $860,3G. MISCELLANEOUS PROBLEMS IN INTEREST. (Art. 100.) The following problems are best nnder- stood by cause and effect, as we have already explained (Art. 84). We only give a few more examples in this place, as being in local order. 1. A loaned 1600 dollars at 6 per cent., until it amount- ed to 2000 dollars ; what was the time ? Ans. 4 years 2 montlis. Cause. Effect. Cause. Effect. 100 : 6 : : 1600 : 400 Statement, • • • 1.2 fl 2. A sum of money was put out at interest, at 7 per cent., and remained 3 years 5 months and 10 days, and the interest was $15,57; what was the principal ? Ans. $64,58. Cause. Effect. Cause. Effect. Q, , , 100 : 7 :: [] : 1^,57 Statement, ... ,^ k-[ 3. At what rate per cent, per annum, will 1200 dollars amount to 1476 dollars, in 5 years and 9 months? Ans. 4 per cent. 4. If 834 dollars, at interest 2 years and 6 mouths, amount to 927 dollars 82^ cents, what was the rats per cent, per annum ? Jlns. 4,1^ per cent. 5. Sixty-three dollars was at interest 1 year 3 mouths, and yielded 4 dollars 72^ cents; what was the rate? .Sns. C. 6. The interest on a certain sum, for 6 years and 3 months, at 6 per cent., was 28|- dollars ; what was the sum? Ans. $75. 7. The interest on 730 dollars, at 6 per cent., was 253 dollars 31 cents; what was the time? Ans. 5y. 9 m. 12 d. 8. Six hundred and thirty dollars was put at interest, at 6 per cent., and the interest received was 25 dollars 20 cents; what was the time out? Ans. 8 months. 9. Seven hundred and fifty dollars was at interest 9 170 ARITHMETIC. months, and the amount received was $789,375 ; what was the rate per cent? ^8ns. 7. 10. If 300 doUars gives 45 dollars interest in 5 years, what was the rate per cent.? Ans. 3. 11. The amount of 750 dollars, at 6 per cent., was 1301 dollars 25 cents ; what time was it out? Ans. 12 y. 3 m. 12. The interest on a certain svim at 4 per cent., for 4 months and 18 days, was 9 dollars 20 cents ; what was the sum ? Ans. $600. 13. In what time will 837 dollars amount to 1029 dol- lars 51 cents, at 5 J per cent.? .dns. 4 years. 14. What sum will amount to 571 dollars 20 cents in 4 years, at 5 per cent.? [This comes under discount.] Ans. $476. 15. The interest on 576 dollars, at 6 per cent., is $60,48; what was the time? Ans. 21 months. PERCENTAGE. (Art. 101.) This indxdes Commission, Broherage and Insurance; all of which is paid at so much per hundred; hence, it is called per-centage, and must fall back on pro- portion ; or, it may be more naturally compared to in- terest, wanting the element of time, or, as in the case of insurance, considering no other than the iinit of time ; but commission and brokerage have no reference to time whatever; we only consider the proportion to the given rate per 100 : hence the following Rule. Jis 100 is to the given rate per cent., so is the given sum to the required commission, brokerage, or insurance.'- Or, proceed in the same manner as though ■* Commission is compensation for selling or buying goods for eth- ers. Brokerage is allowance made to dealers in money or stocks, for the purchase of stock or the exchange of money, or commercial paper. Insurance is money paid to a joint-stock company, for them to assume the hazard and risk of damage by fire, or loss of any kind by sea; and, in case of damage or loss, the company or insurers are to make such loss good, as expressed in the contract. The written PER-CENTAGE. 177 you were required to find the interest of the given sum for one year. EXAMPLES. 1. An agent sold goods for his employer to the amount of 1200 dollars ; what was his conmiission at 5 per cent.-? Statement: as 100 : 5 :: 1200 : to answer. J]ns. $60. 2. Sold goods to the amonnt of 975 dollars 50 cents, on a commission of 7^^ per cent.; what was niv compen- sation? " /]ns. $73, J 6^. 3. A merchant exchanges 3250 dollars of unbankable notes with a broker, allowing him 1^^^ per cent, for par funds ; how much did the broker pay him ? By practice ; thus, at 1 per cent., the broker's bonus or commission would be, $32,50 At i per cent., 16,25 1 " " 8,125 Broker's full commission, $56,875 Therefore, the merchant must receive 3193 dollars 12^ cents, the remaining part of the 3250 dollars. 4. An agent sells 750 bales of cotton, at 48 dollars per bale, and received H per cent. coRimission ; how much did he receive? 750 Q 1 ,. 100 Solution : 2 48 3 .^ns. $540. 5. What must be paid to insure a steamboat and cargo, from Pittsburgh to New Orleans, at a premium of | of 1 per cent., the valuation of the whole being 47500 dollars? /Jns. $356,25. 6. A gentleman in New York has a house valued at 15000 dollars ; he can obtain insurance lor 12000 dollars, at a premium of 2| per cent.: what is his insurance tax ? .^ns. $285. 7. The sales of certain goods amount to 1680 dollars; what sum is to be received for them, allowing 2^ per cent, for commission? ^^ns. $1633,80. instrument expressing such contract, is called a policy The amount of insurance paid, is called the premium. 178 ARITHMETIC. 8. What is the insurance of 760 dollars, at 6!,- per cent.? ^'liis. $49,40. 9. What is the insurance of 5630 dollars, at 7^ per cent.1 ^ns. 436,325. 10. A merchant sent a ship and cargo to sea, in time of war, valued at 17654 dollars; what would be the amount of insurance, at 18} per cent.? .^ns. $3310,12',. 11. What is the brokerage on 21'50 dollars, at 2 per cent.? ^^ns. $43. 12. A merchant shipped, on board a vessel bound from Boston to St. Thomas, goods to the amount of 2464 dollars ; what must he pay to be insured against the dan- gers of the sea, the premium being 2j per cent.? ^)is. $55,44. 13. A merchant having a house, valued at 10650 dol- lars, and goods in his store amounting to 6740 dollars ; what must he pay to be insured against the danger of tire, the premium being U per cent.? ^ns. $260,85. 14. A sends 4500 dollars to an agent, to purchase rail- road stock, and allows the agent 2 per cent, for his trou- ble in making the investment ; how much of the money shall the agent retain? .^ns. $88,23 -f (Art. 102.) In this case, it is evident that the agent must not compute per-centage on that portion of the mo- ney which he may retain. It is only 2 per cent, on the portion spent for his employer. For every 100 dollars the agent spends, he is to have 2 dollars ; then for every 102 dollars, 100 is to go to the principal, and the remain- der to the agent. Therefore, as 102 : 100 : : 4500 : a 4th term. This 4th term is $4411,76 4-? spent for the employer, and the remaining $88,23 -{-, is retained by the agent. Strictly speaking, this is diaeount. (Art. 103.) Neither individuals nor insurance compa- nies will ever insure to the full value of property, as this might create negligence in those who have care of it; or worse, tempt the unprincipled to destroy, or suffer its de- struction, to turn it into cash. Yet, in tiie various turns of business, it is sometimes necessary for individuals to secure a policy for a given specified amount^ even at the expense of paying a higher rate. Such a policy may be STOCKS. 179 wanted, to send before a vcsse' to a foreign port, lo sus- tain the credit of a partner, agent, otr friend, until the in- sured siiip or cargo sliall arrive. To secure a given amount, in case of tlie destruction of the property, we must draw for a higher sum, such a sum as when the per-centage is taken off, will leave the given amount. Now, as all these operations are based on proportion, it is evident that we must take the per-centage from 100: then say, ,fis the remainder is to 100, no is the desired amount to the policy to be taken out. Example 1. A merchant wishes to secure $1920 on an adventure to London ; what sum must be mentioned in the policy to cover that amount, the premium being 4 per cent.? As 96 : 100 :: 1920 : fourth term ; or, 1 : 100 :: 20 : 2000. Jins. $2000. 2. A gentleman has produce on hand to the amount of $14000, which he intends to ship to Soutli America. The marine insurance compaay are willing to insure to the amount of $9000 for 2\ per cent. ; but he wishes to secure $11000, and for this sum they demand a pre- mium of 2| per cent.; what sum must be mentioned in the policy ? Ans. $ 1 1 3 1 1 ,05. 3. A lady has property on which she wishes to secure the sum of $15000; what must be the policy to cover that sum, the premium being 6^ per cent.? Ans, $16042,79. STOCKS. (Art. 104.) Stock is the term given to the aggregate or any number of shares of the capital belonging to any legal association or company, created for any special pur- pose, such as banking, insurance, making public improve- ments, or establishing manufactories. To organize a bank, such as the people will have con- 180 ARITHMETIC. fidence in, it is necessary that it should have ready capi- tal at all times, to redeem its notes ; and to secure this end, a certain amount of capital is designated in the char- ter or legal act of corporation : this capital is divided into shares, H^enerally consisting of $100 each, for which indi- viduals subscribe and pay. These individuals are called stockholders, and receive the profits of the bank, in pro- portion to the shares they hold. Certificates of stock are bought and sold like individual notes or other property ; and when the profits of the company are large, the stock will command more than its nominal value in the mar- ket, and is then said to be above par ; and when the pro- fits are small, the stock sinks below par. The rates above and below par are estimated at so much on, or so much taken ofT of the 100. Hence, we compute the value of stocks by per-centage, as in Art. 101, or Art. 103. EXAMPLES. 1. A sells 25 shares of bank stock at 3 per cent, ad- vance, the par value per share being $100 ; how much money did he receive? ^^ns. $2575. Statement : If 100 give 103, what will 2500 give ? 2. The stock in a certain rail-road company is 15 per cent, below par; what are 12 shares worth, the original value being $50 per share ? ^ns. $510. Statement: 100 : 85 : : 12X50 : .^ns. 3. At a time of great fluctuation in stocks, a gentleman bought 36 shares of the United States Bank stock, nom- inal value $100, at 17|- per cent, advance, and sold the same day at 181^ advance; what did he realize by the transaction ? ^7is. His gain was | of 1 per cent., or $27. 4. If the stock of an insurance company sells for 3i per cent, below par, what are $1200 of the stock worth ? Ans. $1159,50. 5. I directed a broker to purchase for me 75 shares in a certain rail-road company, if he could obtain them at EQUATION OF PAYMENTS. 181 22 per cent below par, promising him f per cent, for his trouble ; what did the whole cost me ? ^ns. $5886,56 -}- [Note. "When the original or nominal value of a share is not mentioned, 100 is understood.] 6. Bought 56 shares in a New York state bank, at 7/, per cent, advance, the original value being $75 per share ; what will the whole cost me, allowing | per cent, to the broker, who made the purchase ? Ans. $4530,75. EQUATION OF PAYMENTS. (Art. 105.) By this is meant the equitable time of paying several debts due at ditferent times, so that neither party siiall sustain any loss of interest. To explain more fully, let us suppose that a person owes his neighbor as follows : 2 dollars, to be paid in 2 months ; 2 dollars, to be paid in 3 months ; and 2 dollars, to be paid in 5 months. In what time shall he pay the whole 6 dollars, so that neither himself nor creditor shall lose interest? We an- alyze it thus : 2 dollars in 2 months will gain as much interest as 4 dollars in 1 month ; 2 dollars in 3 months will gain as much interest as 6 dollars in 1 month ; 2 dollars in 3 months will gain as much interest as 10 dollars in 1 month. Then $6 for the several times will g'ain as much interest as $20 for 1 month. But there are only 6 dollars to be paid, not 20 ; and as interest is always in proportion to the compound of mo- ney and time, we must find ivhat number of months, 182 ARITHMETIC. multiplied by G, will give the same product ari 20, multi- plied by 1 ; and that evidently is -^' =3^- months. From this we may derive the following general Rule. Mulliply each payment by its thne, and di- vide the sum of the several products by the sum of the jjayments, and the quotient will be the equated time for the payment of the whole, EXAMPLES. 1. If 600 dollars are now due, 600 dollars in 4 months, and 600 dollars in 8 months, 600 dollars in 12 months, what is the equitable time for paying the whole ? N. B. It is not necessary in this or any other prob- lem, that we should use the sums of money actually giv- en. It is sufficient that Ave use the same proportional parts. In this case we will use one dollar in place of 600, and the operation will stand thus : IX 0= IX 4= 4 IX 8= 8 1X12=12 4) =24(6 months, ,^ns. 2. If 750 dollars are to be paid, | of it in H years, ~ of it in 2 years, and the residue in 2^ years, what is the equated time of paying the whole at once ? • ./???5. 23 J months. In this example, it is not necessary to use 750 dollars; we had better use 10. 3. A owes B 100 dollars, to be paid in 6 months ; 120 dollars, to be paid in 10 months, and 160, to be paid in 14 months; what is the equated time for paying the whole? .^ns. 10|^r months. 4. A merchant haUi owing to him 300 dollars, to be paid as follows: 50 dollars at 2 months, 160 dollars at 5 months, and the residue at 8 months; and it is agreed to make one payment of the whole ; when must that time be? Jlns. 6 months. 5. F owes H 2400 dollars, of which 480 dollars are EQUATION OF PAYMENTS. 183 lo be paid present, 960 dollars at 5 months, and the rest at 10 months; but they agree to make one payment of the whole, and wish to know the time? A.rins. 6 montlis. 6. A merchant bought goods to the amount of 2000 dollars, and agreed to pay 400 dollars at the time of pur- chase, 800 dollars at 5 months, and the rest at 10 months ; but it is agreed to make one payment of the whole ; what is the mean or equated time I Ans. G months. N. B. To solve the following, we had better fall back on the general principle, and not attempt to apply the rule. 7. A owes B 600 dollars, to be paid in 2 years from the date of the note ; but, at the expiration of 6 months, A agrees to pay 150 dollars, if B will wait enough long- er for the balance, to compensate for the advance ; how long ought B to wait? Ans. 6 months after the 2 years. Here 150 dollars was paid 18 months before the time ; how long shall the remaining 450 dollars remain after the expiration of the 2 years, to give the same interest. Statement: 150X18 : 450X[] : : 1 : 1. m 8. P owes Q 420 dollars, which will be due 6 months hence ; but P is willing to pay him 60 dollars now, pro- vided he can have the rest forborne a longer time ; it is agreed on; tlie time of forbearance, therefore, is required? Ans. 7 months ; that is, 1 month in addition to the 6. 9. A young gentleman has a legacy of 1500 dollars, to be paid him in 16 months ; but, being in want of ready money, agrees to defer the payment of the balance the proper time, if he can have 500 dollars in hand ; when shall the balance be paid ? Ans. 2 years hence. See Art. 80. ^ ^^0 184 ARITHMETIC. PROFIT AND LOSS PER CENT. (Art. 106.) When articles are bought and sold, it is often desirable to know the rate of gain or loss per cent., corresponding to any definite or assumed price. This of course can be done hy proportion, Practice, and proportion. Interest and discount are all the arithmeti- cal principles that can be brought into requisition, under this head ; and practice, interest, and discount, are all re- solvable into joro/)or/20?i; hence proportion alone is the sole i^rinciple, EXAMPI.ES. 1. A merchant bought cotton cloth at 1 shilling 6 pence per yard, and sold it at 1 shilling 10 pence; what was his gain per cent.? pence, pence, gain. Statement: If 18 : 4 : : 100 : how much? Ans. 22f . 2. A grocer bought tea at 60 cents per pound, and sold the same at 75 cents; what was his profit per cent.? Ans. 25. As 60 : 15 :: 100 : Answer Statement: ^.^ 4 . 1 : : 100 : 25 3. I bought Irish linen at 56 cents per yard ; what shall I sell it for, to gain 20 per cent.? Ans. 67 fo- Statement: As 100 : 120 : : 56 : Answer. 4. A merchant sold broadcloth at 4 dollars 75 cents per yard, making a profit of 32 per cent.; what did the cloth cost him ? Ans. $3,60, nearly. Statement: 132, that he now receives, originally cost him 100 ; in that proportion, what did 475 cost? or, as 132 : 100 :: 475 : Answer. 5. A merchant bought English broadcloth ; the first cost, duties and transportation, amount to 14 shillings 8 pence per yard ; what must be his price, in dollars and cents, to gain 20 per cent., the dollar being equal to 4 shillings 6 pence sterling? Ans. $3,91 -|- PROFIT AND LOSS PER CENT. 185 Statement: 100 : 120 :: 14| : price in shillings sterl- ing. But to bring shillings, sterling money, into dollars, we must divide by 4\, or multiply by 2 and divide by 9. Tiie whole combined in one c peration (Art. 24), stands thus : 100 9 44 ^0 4 2 6. If I purchase Irish linen at 2 shillings 4 pence per yard, sterling money, what must I sell it at per yard, in federal money, to gain 30 per cent.? ^^ns. 67^4. 7. A man bought 300 sheep, at 2 dollars 15 cents per head, and his expense in making the purchase, was 45 dollars 50 cents ; he sold them at 3 dollars 20 cents per head; what was his whole gain, and what was his gain percent.? ^ns. Whole gain, $269,50; gain per cent. 39, nearly. 8. If I buy 12'2 hundred weight of sugar for 140 dol- lars, how much must it sell at per pound, to make 25 per cent.? ^ns. 12^- cents. Solved as in Practice (Art. 88), > cents. 140 100 100 125 CWf.' . 12L qr. . . . 4 . lb.. . . 28 This cancels down to the answer. 9. Bought 126 gallons of wine for 150 dollars, and retailed it at 20 cents per pint ; what was the whole gain, and what the gain per cent.? Ans. Whole gain, $51,60; gain per cent. 34|. 10. Bought a hogshead of molasses for 26 cents per gallon, and suppose it lost 5 per cent, in waste and leak- age ; how must I sell the remainder, per gallon, to gain 25 per cent.? Ans. 34yV. 11. If, by selling 1 pound of pepper for 10^ cents, there are % cents lost, how much is the loss per cent.? Ans, 16. J2 186 ARITHMETIC. 12. A merchant bought 180 casks of raisins at 2 dol- lars 13 cents per cask, and sells them at 3 dollars 68 cents per hundred iveif(ht, and gains 25 per cent.; re- quired the average weight in each cask. jlns. 8 1/2 pounds. cost. sale. Solution: 180X213 : 368X[] :: 100 : 125 A proportion wanting a factor to one term, that factor is the number of hundred weis^ht, Avhich must be reduced to pounds, and divided by 180. By Art. 24 : thus, 368 ^^0 4 ^00 213 ;t^0 ^^^ ^ 112 13. A merchant receives raisins, which cost 2 dollars 50 cents per cask, and, by selling them at 5 cents a pound, lie gains 20 per cent, on the first cost ; what was the av- erage weight of each cask ?* ^^ns. 60 lbs. 14. What is the loss, and what is the loss per cent., in laying out 70 dollars for hats, at 1 dollar 75 cents each, and selling them at 25 cents a-piece less than cost? Jns. Whole loss, $10, loss per cent. 14f . 15. A merchant bought 1200 pounds of coffee for 135 dollars ; what must he sell it at per pound, to gain 35 dollars on the whole? »^ns. 14^ cents. 16. Bought 2 hogsheads of wine, at 1 dollar 25 cents per gallon, and sold the same at 1 dollar 60 cents ; what was the whole gain, and the gain per cent.? .^ns.- Whole gain, $44,10; gain per cent. 28. 17. If, by selling cloth at 4 dollars 50 cents a yard, I lose 20 per cent., what was the prime cost? .^715. $5,621. 18. Sold corn at 25 cents per bushel, and lost 3 cents: what was the loss per cent.? ^ins. 10+. (Art. 107.) When persons sell on credit, it is evident that discount must be taken off, before we have the true * This problem is extracted. Its author mentions 200 casks; we omit the number, as it will cancel itself, whatever it be, as seen in the preceding problem. PROFIT AND LOSS PER CENT. 187 profit; also, when goods have been on Imnd some time, the interest of tirst cost shoukl be added on, before we really have the prime cost. 19. Sold goods to the amount of 425 dollars, on 6 months credit, which was 25 dollars more than the goods cost me ; what was the true profit, money being worth G per cent.? JJns. $12,62. 20. A merchant sold goods for 667 dollars, to be paid in 8 months : the same goods, one year ago, cost him 600 dollars, apparently gaining 67 dollars ; what was his true gain, money commanding 6 per cent.? An8. $5,346 -}- [Note. That is, he gained 5 dollars and .34 cents, on the supposition that he traded on borrowed capital, or on the supposition that mterest is 7iot gain. But this is not true ; interest is gain, and legal interest is as much as mere capital ought to gain. In the case under consid- eration, the merchant gained 5 dollars and 34 cents in trading in goods, more than it is supposed he could have done by trading in, or loaning money.] 21. A merchant has had a certain lot of goods on his hands 6 months, and now has an opportunity to sell on 10 months credit, at an advance of 30 per cent, on the original cost ; what are his profits per cent., when he is paying 5 per cent, interest on capital ? .%is. 21i 22. Sold goods to the amount of 723 dollars, ready cash, at 15 per cent, above first cost ; what was my real gain, having had the goods on hand 1 year and 6 months, money being worth 6 per cent.: that is, how much more do I gain by the purchase and sale of the goods than I should have gaified by putting the original cost of the goods at interest? Jhis. $37,73. 23. A grocer bought 3 barrels of sugar, the whole nett weight being 690 pounds, at 8^^ cents per pound, and sells it at 9'^ ; what is his whole gain, and gain per cent.? .^ns I Wliolegain, $10,35. ' 5 Gain per cent. IBfy. 24. A grocer bought 1'. begs of coff'ee, nelt weight of the whole being 1350 pounds, a 12^ cents per pound; 188 ARITHMETIC. what must be his price per pound, to gain $50 on tiie whole ? Ans. 10|- cents. 25. Bought a cask of molasses, containing 42 gallons; 6 gallons leaked out, and I sold the remainder lor 37 \ cents per gallon, and gained 20 per cent. ; what was the original cost per gallon I Ans. 26^^ cents. REDUCTION OF CURRENCIES. (Art. 108.) By this is meant the changing of any sum of money from one sfundard to its equivalent value in another, and involves no other principle than general re- duction ; and, as in general reduction, the operator is guided only by the given tabular values. TABLE OF STATE CURRENCIES. In New England and Virginia, Kentucky and Tennessee. 3 3 18r/. = 0,25 J J 12^ cents=9 pence In New York, Ohio and North Carolina. 2 8 24 d. ■■= ,25 (_ J 25 cents=2 shillings In Pennsylvania, N. Jersey, Delaware and Maryland. 3 5.= ,40 -j or, [.$1=7 5. 6 fZ. =90(7. 9d.= ,10 ( \ ,50=3 s. 9 d.=45 d. £=$10,00'] ■)Sl=,3i3 .s. = 0,50 lor, I $1=6 shillings. d.= 0,25 J J 12^ cents=9 pe: w York, Ohio and North Carolin £=$5,00r "]$1=,4£ 5. =$1,00 4 or, [>$1=8 shillings. d. ■■= ,25 (_ J 25 cents=2 shil inia, N. Jersey, Delaware and Jh £=$8,oor ~)$i=-2je s.= ,40ior,[$l=7s.6d.={ d.= ,10 t J ,50=3 5. 9c/.= South Carolina and Georgia. 7^ =$30,00 ~) •)U = ^\£ 7 s. = 1,50 lor, I $1=4 5. 8 ^Z.=i 4 d.= ,25 J j ,25 = 1 5. 2 c?. , . , =56ff. 14 [Note. In former days, before congress established our national currency, all accounts were kept in pounds, shillings and pence, 4 shillings 6 pence corresponding to REDUCTION OF CURRENCIES. 189 the Spanish dolhir. The several colonies, as these states were then called, issued bills of credit, and passed them as money ; but they soon depreciated, and moie in some tates than in others, and at the general adoption of fede- ral money, the values of the pounds, shilling, Sic. were left as noted in the table. These currencies are legally dead, and ought to be buried; but long habit becomes se- cond nature to most people, and the detestable spirit of avarice serves, in some places, to keep up the distinction. For instance, in New York, where the penny and the cent are very near in value to each other, the petty mer- chants and shopkeepers purchase in cents, and sell in pence, and thereby gain 4 per cent. From the preceding table, to change pounds, shillings, and pence into dollars and cents, we have the following Rules. — 1. Reduce the shillings and pence lo the de- cimal of a pound [Art. 69). Then state the probleyn in proportion, by the relation of £ and $, taken from the table. Or, divide the given number of £^s, and its decimal, by the decimal of a pound that makes a dollar. Or, if it is a vulgar fraction, multiply by its denom- inator, and divide by the numerator, taking care to can- cel, if possible. 2. Reduce the given pounds, shillings and pence, to shillings and decimals of a shilling, and divide by the number of shillings in a dollar; or, if more convenient, reduce all to pence, and divide by the number of pence in a dollar, examples. 1. Reduce 25 pounds 8 shillings 6 pence, New Eng- land currency, to dollars. Operation, 6 12 20 ,3 8,5 25,425 =pounds and decimals of a pound. Ans, $84,75 190 ARITHMETIC. 2. Reduce 42 pounds 10 shillings 3 pence, New York currency, to dollars. 1st Operation. 12 20 ,4 3 10,25 42,5125 2nd Operation. 42 1 5. 3 c/. 20 8)850,25 Ans. $106,281 Ans. $106,281 3. Reduce 120 pounds 7 shillings 9 pence. New Jer- sey currency, to dollars. 120 7 9 20 Is. 6rf.=7,5)2407,75($321,03-f 4. Reduce 38 pounds 5 shillings 6 pence, Georgia cur- rency, to dollars. 12 6 20 5,5 £38,275. Di\dding by /„, gives $161,178+ 5. In 11 shillings 6 pence, Georgia currency, how ma- ny dollars and cents ? Am. $2,464+ 6. In iElOO, New York currency, how many dollars ? Ans. $250. 7. In £100, New England currency, how many dol- lars 1 £ £ $ Statement, . . 3 : 100 :: 10 : $333,33^- Ans. 8. In £100, New Jersey currency, how many dollars ? Ans. $266,66|. 9. Reduce 54 pounds 6 shillings, New England cur- rency, to dollars ? A?is. $181. 10. Reduce 304 pounds 9 pence, New England cur- rency, to dollars ? Ans. $1013,458. 11. Reduce 364 pounds 2 shillings 6 pence, New York currency, to dollars ? Ans. $910,31 + REDUCTION OF CURRENCIES. 191 (Art. 109.) The reverse operations will, of course, bring dollars to pounds. In New England currency, 1 dollar equals f^^ of a pound; in New York currency, 1 dollar equals y\ of a pound ; in New Jersey currency, 1 dollar equals f of a pound ; hence, to reduce dollars to pounds, we must take the following Rule. Multiply the dollars ayid decimals of a dollar by the value of a dollar^ expressed in parts of a pound. EXAMPLES. 1. In 45 dollars 75 cents, how many pounds, shillings and pence, New England currency ? 45,75 ,3 13,725 20 14,500 12 6,000 Ans. ^13 14 s. Q d. 2. Reduce 90 dollars to pounds, mon, are to sustain a specific loss, or raise a specific tax, tlie opera- tion of determining each man's portion of the gain or loss, is called single fellowship. This is not applicable to business partnerships, as generally conducfcd, in which a fixed proportion of the profit or loss is usually agreed upon between the parties, and the disparity in the amount of capital is compensated by personal services, or by an allowance of interest on the excess furnished by either. In single transactions, such as fall under single fellowship, it is plain that he who furnished most capital, either iu money or labor, must have most of the profit; and he who hazards most in any adventure, must sustain most of the loss, when loss occurs ; and just in propor- tion to that capital, or tliat hazard, compared to the capital or hazard of others. Hence fellowship is but another application of that pure 2>rinciple of pro- portion, which, as applied to such cases, may be express- ed thus : As the whole amount of stock or labor Is to each man's portion. So is the whole property, loss or gain, To each man's share of it. Proof. The sum of all the shares must equal the whole gain, &c. 204 ARITHMETIC. exa:«ples. ^l. Three workmen having undertaken to do a piece of work for 275 dollars, agreed to divide their protits in proportion to the amount of labor each one performed. M labored 50 days, N 65 days, and O 85 days ; what was the share of each? Solution: • • M = 50 days. N=:65 " 0=85 " Sum, 200 Divide by 25, and 8 Also, 8 And 8 : $275 : 50 : : 11 : 50 : : 11 : 65 : : 11 : 85 : $68,75 =M's 89,37?, = N's 116,87i = 0's $275,00 Proof. 2. A man bequeathed to the eldest of his four children 2400 dollars ; to the second, 2000 dollars : to the third, 1800 dollars, and to the youngest, 1600 dollars, or in that proportion of the value of his real estate; but, on the set- tlement, only 4000 dollars were found to divide ; what was the share of each ? N. B. It is not necessary to use the identical numbers given ; it is sufficient to use numbers that bear the same relation. Hence we take, 1st. 12 2d. 10 3d. 9 4th. 8 39 : 4000 12 123J3- dollars = 1st. * Here we compare days' work with dollars. It has been asserted by many, in modern times, that we cannot compare unhke things, and that such comparisons are absurd, &c.; but we think these views over nice, at least. It is true we cannot measure unlike things by each other, but we can compare their numerical vahies. In the pre- sent instance, who can doubt the philosophy of comparing the days' work to the dollars received, to see whether one is more or less innu- vierical amount, than the other] Yet, as a general thing, we admit it is more clear to compare quantities of like kind; and while we make this admission, we do not concede that it is more philosophical. FELLOWSHIP. 205 3. A man is indebted to A $250,50, to B $500, to C $349,50; but when he comes to nmke a settlement, it is found he is worth but $960; how much will each one receive, if it be in proportion to their respective claims? fA $218,618-1- Ans. \ B $436,363-f (^C $305,018-1- 4. Four men hired a coach to convey them to their re- spective homes, which were at distances from the place of starting as follows: A's 16 miles, B's 24 miles, C's 28 miles, and D's 36 miles ; what ought each to pay, as his part of the coach hire, which was 13 dollars? Ans. A $2, B $3, C $3,50, and D $4,50. 5. Divide 360 dollars in the proportion of 2, 3 and 4. Ans. 80, 120, 160. 6. In the year 1835, three men, P, Q, and R, made a joint capital of 7500 dollars, to purchase city lots in Buf- falo; P put in 1500 dollars, Q 2500, and R the remain- der ; ihey soon gained paper obligations to the amount of 18000 dollars; what was each partner's share of the gain? rP=$3600. rp=i LR=! Ans. < Q=$8000. :$8400. (Art. 115.) Taxes. The taxable inhabitants of any city, town, or county, are all in political fellowship, for the payment of taxes and support of government. A small tax in some states, and in most foreign governments, is imposed on every male citizen above a certain age, and being the same to all, independent of property, is called per head, or per poll, or poll tax. In addition to this, tliere is a tax on property, both fixed and movable : i. e. real and personal : the amount of which property is determined by official appraisers, called assessors, and their list of persons, and property held by each, is called the assessment-roll. All persons on this roll are, as we before observed, in felloivship. When the amount of tax is determined upon, (the poll-tax of the district, if any) is taken out, and the remainder divided out among the inhabitants, in proportion to their division of property. 20G ARITHMETIC. EXAMPLES. I. If a t:ix of 3000 dollars be assessed upon all the taxable property of a toM'ii, the valuation of which, on the assessment-roll, is 600,000 dollars, what will it be on 1, 2, 3, 4, &c., to 10 dollars ? what will it be on 100 and 1000 dollars? Solution: As 600000 : 3000 :: 1 : 4th term. Or, as 200 : 1 :: 1 : _i-.-=,005 = 5 mills. r$l pays ,005 $6 pays ,03 2 " ,01 7 " ,035 Ans. < 3 " ,015 8 " ,04 4 " ,02 9 " ,045 L 5 '* ,025 10 " ,05 100 " ,50 1000 " $5,00 The property of John Wells, in this town, is assessed at $2780 ; what is his property tax ? As $1000 pays $5, $2000 pays $10,00 700 pays 3,50 80 pays ,40 Therefore, 2780 pays $13,90, Ans, In the same manner, estimate the tax of any other indi- vidual inhabitant who possesses taxable property. 2. The corporation of a city vote to raise an extra tax of$5400 for certain public improvements, and the assess- ment-roll sums up to $2,700,000 ; what is the extra tax on a dollar, and liow much extra tax must A pay, who is taxed for $3757 ? Ans. 2 mills on a dollar: A pays $7,515. 3. A tax of 3000 dollars is to be raised in a certain town, where the taxable property amounts to 120000 dol- lars, and the number of polls 320, at 50 cents each ; what is paid on a dollar, and what is A's tax on a pro- perty valuation of 2500 dollars ? Ans. ,023| on $1 ; A's tax, $59,16|. COMPOUND FELLOWSHIP. 207 COMPOUND FELLOWSHIP. (Art. 116.) There are certain cases of fellowship that compel lis to take time into consideration. The produc- tive vaUie of stock depends on the amount of capital, by the time, as in interest, or the amount of labor depends on the number of laborers, by the time they labor, &c. All such cases must be considered under a compound, of which time is an element; hence it is called compound fellowship. The following example will fully illustrate this principle : Three men hired a pasture lot for 25 dollars ; A put in 5 cows, 12 weeks; B 4 cows, 10 weeks; and C 3 cows, 15 weeks; what part of the 25 dollars shall ench pay ? Here it is evident, that the number of cows, each put in, cannot decide the question, nor can the time alone de- cide ; we must take tJie compound of both these elements, thus : 5 cows 12 weeks =60 cows 1 week. 4 cows 10 weeks =40 cows 1 week. 3 cows 15 weeks =45 cows 1 week. The whole pasturage is, then, the same as 145 cows 1 week ; and the time is thus reduced to unity, and then solved by single fellowship; thus, 145 : 25 :: 60 : A's part. or, . . 29 : 5 : : 60 : A's part. A=$10,344 -{- 29 : 5 :: 40 : B's part. B= 6,897 + 29 : 5 :: 45 : C's part. C= 7,758 4" Froof, $24,999 + lit the same way, we estimate labor, as well as con- sumption, interest,' &c., and from this we draw the fol- lowing Rule. Multiply the active ager.ts by the time each was in action; or, if the agent is money or stock, mul- tiply each man's stock by its time, and add the several products together. Then by proportion, 208 ARITHMETIC. As the sum of the products Is to each particular product, So is the wJiole gain or loss To each man's share of the gain or loss. EXAMPLES. 1. Three merchants traded together; A put in 120 dollars for 9 months, B 100 dollars for 16 months, and C 100 dollars for 14 months, and they gained 100 dollars; what is each man's share ? $ mo. A's stock 120X 9 = 1080 B's stock 100X16=1600 C's stock 100X14 = 1400 Sum, 4080 Then, as 4080 : 1080 :: 100 or, as ... 102 : 27 : : 100 : $26,47 -f A's share, &c. 2. Two men commenced partnership for a year; one put in 1000 at the commencement, the other put in his capital 4 months afterwards ; at the close of the year they divided equally ; what capital did the second put in ? Ans. $15tl0. N. B. Many problems must be solved, rather by the general principle, than by the general rule. In the above example, if they shared equally, the products of their capital and time must be equa4. 3. A, B, and C, made a stock for 12 months; A put in, at first, 873 dollars 60 cents, and 4 months after, he put in 96 dollars more ; B put in, at first, 979 dollars 20 cents, and at the end of 7 months, he took out 206 dol- lars 40 cents ; C put in, at first, 355 dollars 20 cents, and 3 months after, he put in 206 dollars 40 cents, and 5 months after that, he put in 240 dollars more. At the end of 12 months, their gain is found to be 3446 dollars 40 cents ; what is each man's share of the gain ? rA's share is $1362,88 .^ns. -i B's 1298,34-j- [C's 785,13 4. Three men took a field of grain to harv'est and thrash, for \ of the crop; A furnished 3 hands 4 days, COMPOUND FELLOWSHIP. 209 B 2 hands 5 days, and C 4 hands 6 days ; the whole crop amounted to 320 bushels ; what was each partner's share ? Ans, rA's=20|f. J B's = 17i'3- (.C's=4Ui. 5. A, B, and C, had a capital stock of 5762 dollars. A's money was in trade 5 months, B's 7, and C's 9 ; they gahied 780, which was divided in the proportion of 4, 5, and 3 ; that is, A 4, as often as B 5, and C 3 ; now B received 2087 dollars, and absconded ; what did each gain, and put in ; and what did A and C gain and lose by B's misconduct? f A's stock $2494,887 gain 260 ^ J B's do. 2227,577 do. 325 ^^^' 1 C's do. 1039,536 do. 195 LA and C gain $465,577 [Note. As money, in compound fellowship, is divided in proportion to each man's capital, multiplied by its time in trade; inversely, then, each man's capital must be in proportion to his gain, divided by the time his money was in trade. Therefore, as their shares of the gain are as the numbers 4, 5, and 3, their capital stocks must be in proportion to |-, 4 and i.] 6. In a certain factory were employed men, women and boys ; the boys receive 3 cents per hour, the women 4, and the men 6 ; the boys work 8 hours a day, the wo- men 9, and the men 12 ; the boys receive 5 dollars as often as the women 10 dollars, and for every ten dollars paid to the women, 24 dollars were paid to the men ; how many men, women and boys were there, the whole num- ber being 59 ? Jlns. 24 men, 20 women, and 15 boys. 7. A, B, and C, united with 1930 dollars ; A's money was in trade 3 months, B's 5, and C's 7 ; they gained 117 dollars, which was so divided that | of A's share was equal to ^ of B's, and to \ of C's ; what did each gain, and put in ? ^ C A gained $26, B $39, and C $52. *^"*' I A's capital was $700, B's $630, and C's $600. 8. A, B, and C, are employed to do a piece of work for 26 dollars 45 cents ; A and B together are supposed 72 """" 210 ARITHMETIC. to do ^ of it ; A and C j\, and B and C i|, and are paid proportionally to this supposition ; what is each man's share of the money ? ^7is. A $11,50, B $5,75, C $9,20. BARTER. (Art. 117.) Barter is striking the balance of trade, or determining how much of one article is equal to a giv- en quantity of another, or several others; and, of course, involves no new principle of computation. The nature of the case before us must determine the mode of opera- tion. Rules. Practice. Rule of Three. EXAMPLES. 1. A farmer bartered 3 barrels of flour, at 5 dollars 25 cents per barrel, for sugar and coflee, to receive an equal quantity of each; how much of each must he receive, admitting the sugar to be valued at 9 cents per pound, and the coffee at 15 cents ? ^^n.s. 65|. 2. Sold 75 barrels of herrings, at 2 dollars 75 cents per barrel, for which I am to receive 75 bushels of wheat, at 1 dollar 8 cents per bushel, and the residue in money; how much money must I receive? ^ns. $125,75. 3. Sold 35 yards of domestic, at 20 cents per yard, and am to receive the amount in apples, at 25 cents per bushel ; how many bushels must I have ? ^is. 28 bushels. 4. What is rice per pound, when 340 pounds are given for 4 yards of cloth, at 4 dollars 25 cents per yard ? ^ns. 5 cents. 5. Gave in barter 65 pounds of tea for 156 gallons of rum, at 33^ cents per gallon ; what was the tea rated at ? .^ns. 80 c. per lb. 6. How many pounds of butter, at 12^ cents per pound, must be given in exchange for 9| pounds of In- I digo, at 235 cents per pound ? ^?is. 183y\ lb. BARTER. 21 7. A merchMnt bought 80 yards of broadcloth, at 3-^^ dollars per yard, and paid in coifee at 10 pence per pound, New York currency, how many pounds did it require? Arts. 2496 pounds, 8. Sold 24 hundred weight of hops at 4 pence per pound, and took pay in sugar at 6 pence per pound ; how many pounds did I require? Ayis. 16 cwt. 9. Sold 5 hundred weight 1 quarter of sugar at 8 dol- lars 50 cents per hundred weight, and received for pay 21 yards of cloth; what was the cloth per yard? Jlns. $1,12^. All the examples thus far, except No. 2, can be solved very briefly by Art. 24. No. 2 is also very brief, but not in that form. 10. Q has coffee worth 16 cents per pound, but in bar- ter, raised it to 18 cents; B has broadcloth worth 4 dol- lars 64 cents per yard ; what must B raise his cloth to, so as to make a fair barter with Q ? Ans. $5,22. 11. P and Q barter; P has Irish linen, worth 3 shil- lings 7 pence, cash, but, in barter, he will have 3 shillings 10 pence ; Q delivers him broadcloth at 1 pound 16 shil- lings 6 pence per yard, worth only 1 pound 13 shillings; how much linen does P give Q for 138 yards of broad- cloth, and which gains by the bargain ? and how much in dollars and cents, the whole being in Irish currency ? Jins. P gives 1314 yards ; Q gains $ 33-|- » because his cloth is proportionally too high. 12. A and B barter; A has 150 gallons of brandy, at 7 shillings 6 pence per gallon, cash, but in barter he will have 8 shillings ; B has linen at 3 shillings 6 pence per yard, ready money; how much must it be per yard, to meet A's bartering price, and how many yards are equal to A's brandy ? Ans. Barter price, 3 s. 8f d.; B must give A 321i yards, nearly. 212 ARITHMETIC. SECTION V. MENSURATION.* (Art. 118.) Mensuration is finding, or defining, the numerical contents of surfaces and solids, and its founda- tion is the science of geometry; but its every-day appli- cation to the mechanical business of life, demands a place for its practical rules in every arithmetic. Some of these rules are obvious, from inspection: otiiers must be taken on trust, until the pupil studies geometry, from whence they are drawn ; we shall, however, give some of the common illustrations. All surfaces, of whatever figure, are referred to squares for measurement, and the iinit may be taken at pleasure ; it may be an inch, a foot, a yard, a rod, a mile, &c., according as convenience and common sense may dictate. The following figures will render the truth of several rules apparent: Fig. 1 . A square. Fig. 2. A right angled parallelogram. 12 3 4 5 6 7 The first, a square, the side of which is 3 units in length ; and it is apparent to the eye, that the whole square contains 9 square units ; and, considering the 3 * Most writers on arithmetic have placed mensuration after the square and cube roots ; but we think it an injudicious arrangement, as, in the operations of finding roots, mensuration is almost univer- sally used. MENSURATION. 213 units in a side as feet, the whole square is one square yard, containing 9 square feet, agreeably to the dictation of the square, measure table. By figure 2nd, we perceive that the number of litde squares it contains, is equal to the iniits in lengtli, mul- tiplied by the units in breadth, which must be true in every case. (Art. 119.) If the sides are not at right angles, as in figure 3d, we must multiply its length by its jierpendic- idar breadth, as it is proved in geometry, that the fiffure ABCG = L!ie figure BCDE. Fig. 3. A right and an oblique-angled parallelogram. A E G D A triangle is equal to half of a parallelogram, of the same base and altitude, as is obvious, from inspecting fig- ure 4, AC=the base, and BE=the altitude. B D Fig. 4. A plain figure having 4 sides, and 2 of them parallel and unequal^ is called a trapezoid. It is rigidly proved, in geometry, that the area of such a figure is found by multiplying its perpendicular altitude EF, by a medium base between AD and BC. This truth is apparent, from the inspection of Fig. 5. BEG D 2U ARITHMETIC. Fig. 6. / g\ \ ^ ; (Art. J20.) When a circle is inscribed in a squaie, it lias been ascertained by geometry, that the area or sur- face of the circle occupies ,7854 (as near as can be ex- pressed with 4 decimals,) of the whole square. Bu* the square is the square of the diameter of the circle, '«s ap- pears from figure 6. Therefore, to find the area of a circle, we may square the diameter, and multiply it by the decimal ,7854. It is also shown in geome- try, that the circumference of a circle is 3,1416, nearly, when the diameter is 1 ; and when the diameter is 2, the circumference will be double, and so on in proportion : ten times in diameter giving ten times for circumference, &c. &lc. Again: in figure 6, from the centre C, we can draw radii CD, CG, as near each other as we please; and if we draw them extremely near each other, the small part of the circumference GD, may be considered a straight line, and the sector CDG, a triangle ; but the area of this triangle is equal to CD, multiplied by \ of GD. But the whole circle can be filled up with such triangles : hence the area of the whole circle is equal to V of its diameter, multiplied by \ of all the GD's, or ^ of the whole circumference. Squares, circles, and all fig- ures of a similar shape to one another, are, in area, as the square, of their like dimensions. That is, a circle of double diameter to another, is 4 times in surface, of .3 times in diamefe^-r, 9 times in surface, &c. &:c. This may be brought to the mind by inspecting figure 1. If we call the whole square in fiffure 1 an unit, then the square of 1 is J^'; that is, to square a fraction, square its numera- tor and denominator: geometrical figures and numericals agree. .-VIE.NSl KATIOX. 215 RIXAPITULATION. To find the surface or area of a square. Rule 1. Multiply its equal length and breadth to- gether. To find the area of a parallelogram. Rule 2. Multiply length and breadth together, (ta- king care always to measure them at right angles.) To find the area of a triangle. Rule 3. TVlien the base and altitude are given, mul- tiply one by half the other. When not a right angle, and the altitude not known, but the three sides given, the following is the rule which the mere arithmetician must take on trust. Rule 4. Add all the three sides together, and take half that sum. Next, subtract each side severally from the said half sum, obtaining three remainders. Then multiply the said half sum and those three remainders all together, and extract the square root of the last pro- duct, for the area of the triangle. To find the area of a trapezoid, or a figure of 4 sides, and only two opposite sides parallel. Rule 5. Add the two parcdlel sides together, and take half the sum : this will be the mean or average width. Multiply this mean vndth by the perpendicular distance between the parallel sides> To find the area of a circle. Rule 6. Square the diameter, and multiply that square by the decimal ,7854. Or, when most convenient. Multiply half the diam- eter by half the circumference. [Note. Tlie circumference to the diameter of any cir- cle, is found to be very nearly in the proportion of 22 to 7: a more accurate ratio is .3,1416 to 1.] To find the surface of a globe or sphere. Rule 7. Multiply the circumference and diameter toor.ther : or, inultiply the square of the circumference 6y 3,1416. 216 ARITHMETIC. This rule must be taken on authority. For proof, see Geometry. Definitions. A right cylinder is a round body of uniform diameter ; its two ends parallel and at right an- gles with its length. Conceive the surface of such a cy- linder cut lengthwise and rolled out, it will form a paral- lelogram whose width is the circumference of the cylin- der ; therefore, to find the surface of a cylinder, we have the following Rule 8. Multiply the length by the circumference. A right cone may be covered by a multitude of equal isosceles triangles, whose base is the base of the cone, and whose altitude is the slant height of the cone ; there- fore, To find the surface of a right cone. Rule 9. Multiply the circumference of the base by half the slant height. To find the area of an ellipse. Rule. Multiply the two diameters together, and that product by the decimal ,7854. EXAMPLES UNDER THE FOREGOING RULES. 1. There is a square of 80 rods on a side, and a par- allelogram also of 80 rods each side ; but from the base to the opposite side is only 70 rods of perpendicular dis- tance ; what is the difference in area of these two figures? Jim. 800 rods. 2. How many yards in a triangle whose base is 148 feet, and perpendicular 45 feet ? .^ns. 370 yards. 3. The three sides of a triangle are severally 60, 50, and 40 rods ; how many acres does it contain ? ^ns. 61. 4. On a base of 120 rods, a surveyor wished to lay off a rectangular lot of land containing 40 acres ; what dis- tance in rods must he run from his base line ? Jlns. 5S^ rods. 5. How many boards will it require to cover the body of a barn 60 feet long, 40 feet wide and 20 feet high, to MENSURATION. 217 the eaves, the boards being on an average 15 inches wide and 10 feet long? Ans. .S20 hoards. 6. How many feet in a board 22 inches wide at one end, 8 inches wide at the other, and 14 feet long? ^ns. 17^ feet. 7. A board is 9 indies wide ; how much in length will it require to make 6| square feet? .'?».s-. 8| feet. 8. The bottom of a circular cistern is 5^ feet in diam- eter ; how many square feet of surface ? .^ns. 23,758+ feet. 9. What quantity of surface in a cylinder 30 feet long and 3 feet in diameter, the two ends included ? £ns. 296,88-}-feet. 10. A man bought a farm 198 rods long, and 150 rods wide, and agreed to give $32 per acre ; what did the farm come to ? ^ns. $5940. N. B. Make no attempt to compute the number of acres definitely. 11. If the forward wheels of a coach are 4 feet, and j the hind ones 5 feet in diameter, how many more times will the former revolve than the latter, in going a mile ? .dns. 84. N. B. In this problem use 7 to 22. The solutions of the foregoing problems are all very brief by canceling, except ihe 3d and 9th. (Art, 121.) The foregaing rules apply to Plasterers^ Pavers^ and Carpenters^ loork. These artificers sfener- ally compute their work at so much a square yard, or^o much for 100 square feet, which last is sometimes called a carpenter's square. To compute the number of square feet, yards, &;c., the length, breadth and heighth of a room is taken in feet and inclies, never measuring closer than inches. In books, we often meet with feet, inches, thirds, fourths, 25. 132 feet. 36. The ditch of a fortification is 1000 feet long, 9 feet deep, 20 feet broad at bottom, and 22 at top ; how much water will fill the ditch? ^ns. 1158127 gals, nearly. 37. Seven men bought a grind-stone, of 60 inches diameter, each paying \ part of the expense ; what part of the diameter must each grind down for his share ? ■Ans. The 1st, 4,4508, 2d, 4,8400, 3d, 5,3535, 4th, 6,0765, 5th, 7,2079, 6th, 9,3935, 7th; 22,6778 inches. 38. How many rods less will it take to fence in an acre, if it be laid out in the form of a circle, than in the form of a square 1 ^^ns. 5|+rods. 39. How many pieces of cloth, at 20,8 dollars per PROMISCUOUS EXAMPLES. 279 piece, are equal in value to 240 pieces, at 12,6 dollars per piece ? ^^ns. 145,38+pieccs. 40. If, when tlie price of M'heat is 74,6 cents per bush- el, the penny roll weighs 5,2 ounces, what should it be per bushel when the penny roll weighs 3,5 ounces ? Ans. $1,108. 41. If a globe of stone, 9 inches in diameter, weifrli 36 pounds, liow much will another globe of the same kind of stone weigh, whose diameter is 15 inches ? Ans. 166,6-4-lbs. 42. Mix 6 bushels of oats, worth 20 cents per bushel, with 8 bushels of oats, worth 25 cents per bushel, to rye, worth 70 cents per bushel, and wheat worth 80 cents — and sell the mixture at 75 cents per bushel ; how much rye and wheat must there be in the mixture 1 Ans. Rye, 14 bush.; wheat 160 bush. 43. Seven men not agreeing with the owner of a board- ing house, about the price of boarding, offer to give 100 dollars each, for as long time as they can seat themselves every day differently at dinner; this offer being accepted, how long may they stay ? Ans. 5040 days, or 13 years 295 days. 44. What will be the expense of paving a rectangular yard, whose length is 63 feet, and breadth 45 feet, in M'hich there is laid a foot-path 5 feet 3 inches broad, run- ning the whole length, with broad stones, at 36 cents a yard ; the rest being paved with pebbles, at 30 cents a yard ? Ans. $96,70^. 45. In exchanging 20^ yards of cloth, of 1^ yards wide, for some of the same quality, of J of a yard wide, what quantity of the latter makes an equal barter ? Ans. 34^ yards. 46. Suppose a large wheel, in mill-work, to contain 72 cogs, and a smaller wheel, working in it, to contain 50 cogs ; in how many revolutions of the greater wheel, will the lesser one gain iOO revolutions ? Ans. 227 j 1 1 APPENDIX MECHANICAL POWERS. The mechanical powers properly belong to Natural Philosophy, and not to Arithmetic. The problems per- taining to them, in a numerical point of view, are usually very trifling ; but the principles on which the computa- tions are based, require exact thought, and should not be passed over in a careless manner. We make these ob- servations to guard the pupil against imbibing the error of measuring the importance of a thing by the difficulty or ease of numerical computations. Properly speaking, there are but two fundameotal me- chanical powers, viz.: the lever and inclined plane. From the lever, we derive the pulley, and wheel and axle. From the inclined plane, we derive the screw and the ivedo^e. Theoretically, the lever is an imponderable and inflex- ible bar, supported on a fixed point, called the fulcrum. Let the line AB represent it, resting on the point C, call- C ed the fulcrum, and weights A j B that balance each other at A and B. 'I'he fiffure below represents the application of the power of the lever as used in jjrying. 28Q ARITHMETIC. 281 In natural philosophy the term, momentum, means quantity of force; and two bodies of unequal weight can have the same momentum if their degrees of motion are reciprocal to their weight. A body in motion, will require a certain resistance to stop or overcome its motion : if its motion were twice as rapid, the resistance must be twice as great to produce the same eflect. If two bodies move with the same velocity, and one of them double the weight of the other, it is evident that it would require double the resistance to stop the heavier body, that would be required to stop the other. This amount of resistance is equal to the momentum, and evi- dendy depends on the compound, or product of weight multiplied by velocity. When two bodies balance each other over the fulcrum point of a lever, the momentums on each side of the ful- crum must be equal. Conceive the two bodies, A and B, (first figure on the preceding page,) to balance on the point C, and give the bar a slight motion round the fixed point C. If A is twice as far from C as B is from C, it is evident that A will move twice the distance that B will, in the same time. If A is three times as far from C as B is from C, then A will have three times the motion that B will have, &LC. ^. J)r. Balance. Cr. Apl.l To D. Judkins, T. Yr. Coolidge, H. Ames, T.Hilton, J. Wilson, G. Hamilton, T. P. Letton, 4 30 7,17 •2; 23:95 1006 1085 10.50 15 50 82.33 I Apl.l By R. Young, " J. Moore, " H.Sanxay, 34 .54 Note. — This account exhibits the exact state of your books. It is made from the preceding accounts in the Leger. The Dr. side is an exhibit of the amounts due to you by others, and the Cr. side the amounts due hy you to others. It is not strictly ne- cessary that this account should be introduced in the Leger in single entry : it will be found convenient, however, to balance the .1 The Cash Boole. book at stated intervals, and transfer tlie balances to the new accounts below, as in the preceding Leg-er, and when that is done, a balance account like the above, will be found convenient, as presenting, at one view, the exact state of your Leger. FORM OF A BILL FROM THE PRECEDIXG. Mr. David Judkins, 1852 To Edward Thomson, Br. To 10 lbs. coffee at 17 cts $1 70 25 lbs. suo-ar at 10 cts 2 50 Jan. 4 (C 30 Mar 8 Jan 8 30 12 bbls. apples at 75 cts. 200 lbs. flour at $175,.. Cr. By Cash, P 00 47 bushels corn at 20 cts 9 40 Errors excepted. Balance due,' 4.30 Rec'd Payment in full, EDWARD THOMSOJS". — '— 4 20 9 00 3 50 16 12 70 40 THE CASH BOOK. The Cash Book is used to record the daily receipts and pay- ments of money. It is ruled nearly the same as the Leger ; the Dr. side exhibits the amonntof money received, and the Cr. side, the amount paid mit. Subtraat the sum of the Cr. from that of the Dr. and the balance will always be equal to the amount of cash on hand. FORM OF A CASH BOOK. Dr. Cash. a-. 1852 Jan. 1 " 1 " 1 " 1 To cash on hand. Cash of J. Young, H. Sanxay, ' D.Juclkins, I ',1852 i 73 81 j 'Jan. 1 By house rent pd. 16 40 ' 25 00! lOiOO T. P. Lctton, iPd. note R. Hand, 1 Family expenses, 1 By cash on hand, ! 125 21 Jan.2iTo cash on hand, 1 " 2CashofTCoolidge •' 2 Cash found. Jan. 3 To cash on hand. 52 84 By cash pd. Ames 2316 Jan. 2 & Smith, 29 00 ! " 2 By cash on hand, 105,00; "85 001 18 00 50 00 4 37 52 34 125 21 = = ! 20 00 ! S5 00 — , — 105 00 ^^ ^^^ i p VB 35835 JACOB EENSJl ir iiei irrr;}» mi'eei, ViticimiuU, Ohio, }3ubli£ii!cr of Hobinson s i^lathcuialkal Scriee. i do. I7aii;\;.i ; ;;'losO; do. (^eon'eii_ do. .vstiYx;. chooi FditJL ISi""l:: • ■ of AlAiKU W"Ai--;cu ;; r^nooi Dictioriu; N'^" "^ n"=! Eieiner.t? ofScicr 1'he • ^ rraoiiiu. a collectl'^ri oi i ,;:-. Sera "^ i Cap, Comr'i- I Drawing i'oi . > .^ ^ i Blanks f ai! i:^.e varlcn- ■3 voices, 38 llj ■ '' - TE .u-iCoiu' :j .JJ!