and 5 units. We can now, in the mind, suppose I ten taken from the 8 tens, which would leave 7 tens, and this I ten we can suppose joined to the 5 units, making 15. We can now take 7 from 15, as before, and there will remain 8, which we set down. The taking of 1 ten out of 8 tens, and joining it with the 5 units, is called borrowing ten. Proceeding to the next higher order, or tens, we must consider the upper figure, 8, from which we borrowed, I less, calling it 7; then, taking 2 (teus) from 7, (tens,) there will remain 5, (tens,) which we set down, making the difference 58 dollars. Or, instead of making the upper figure I less, calling 7, we may make the lower figure 1 more, calling it 3, and the result will be the same; for 3 from 8 leaves 5, the same as 2 from 7. 19. A man borrowed 713 dollars, and paid 471 dollars; how many dollars did he then owe? 713-471 how many? Ans. 242 dollars. Ans. 1147. Ans. 36969. 8. The pupil will readily perceive, that subtraction is the reverse of addition. 22. A man bought 40 sheep, and sold 18 of them; he left? 40 - 13 = how many? how many had Ans. 22 sheep. 23. A man sold 18 sheep, and had 22 left; how many had he at first? 18+ 22 how many? Ans. 40. 24. A man bought a horse for 75 dollars, and a cow for 16 dollars; what was the difference of the costs? 75-16 how many? Reversed, 5916 = how many? how many? how many? 25. 114- 103= how many? Reversed, 11+ 103 26. 14376 how many? Reversed, 67 +76 Hence, subtraction may be proved by addition, as in the foregoing examples, and addition by subtraction. To prove subtraction, we may add the remainder to the subtrahend, and, if the work is right, the amount will be equal to the minuend. To prove addition, we may subtract, successively, from the amount, the several numbers which were added to produce it, and, if the work is right, there will be no remainder. Thus 78621; proof, 21 —6—15, and 158 7, and 7 — 7 = 0. From the remarks aud illustrations now given, we deduce the following RULE. 1. Write down the numbers, the less under the greater, placing units under units, tens under tens, &c., and draw a line under them. II. Beginning with units, take successively each figure in the lower number from the figure over it, and write the remainder directly below. III. When the figure in the lower number exceeds the figure over it, suppose 10 to be added to the upper figure; but in this case we must alt to the lower figure in the next columnn, before subtractng. This is called borrowing 10. EXAMPLES FOR PRACTICE. 27. If a farm and the buildings on it be valued at 10000, and the buildings alone be valued at 4567 dollars, what is the value of the land? 28. The population of New England, at the census in 1800, was 1,232,454; in 1820 it was 1,659,854; what was the increase in 20 years? 29. What is the difference between 7,648,203 and 928,671 ? 30. How much must you add to 358,642 to make 1,487,945? 31. A man bought an estate for 13,682 dollars, and sold it again for 15,293 dollars; did he gain or lose by it? and how much? 32. From 364,710,825,193 take 27,940,386,574. 33. From 831,025,403,270 take 651,308,604,782. 3. SUPPLEMENT TO SUBTRACTION. QUESTIONS. 1. What is subtraction? 2. What is the greater number called? the less number? 4. What is the result or answer called? 5. What is the sign of subtraction? 6. What is the rule? 7. What is understood by borrowing ten? 8. Of what is subtraction the reverse? 9. How is subtraction proved? 10. How is addition proved by subtraction? EXERCISES. 1. How long from the discovery of America by Columbus, in 1492, to the commencement of the Revolutionary war in 1775, which gained our independence? 2. Supposing a man to have been born in the year 1773, how old was he in 1827 ? 3. Supposing a man to have been 80 years old in the year 1826, in what year was he born? 4. There are two numbers, whose difference is 8764; the greater number is 15687; I demand the less. 5. What number is that which, taken from 3794, leaves 865? 6. What number is that to which if you add 789 it will become 6350. 7. In New York, by the census of 1820, there were 123,706 inhabitants; in Boston, 43.940; how many more inhabitants were then in New York than in Boston? 8. A man, possessing an estate of twelve thousand dollars, gave two thousand five hundred dollars to each of his two daughters, and the remainder to his son; what was his son's share? 9. From seventeen million take fifty-six thousand, and what will remain ? 10. What number, together with these three, viz. 1301, 2561, and 3120, will make ten thousand? 11. A man bought a horse for one hundred and fourteen dollars. and a chaise for one hundred and eighty-seven dollars; how much more did he give for the chaise than for the horse? 12. A man borrows 7 ten dollar bills and 3 one dollar bills, and pays at one time 4 ten dollar bills and 5 one dollar bills; how many ten dollar bills and one dollar bills must he afterwards pay to cancel the debt? Ans. 2 ten doll. Lills and 8 one doll. 13. The greater of two numbers is 24, and the less is 16; what is their difference? 14. The greater of two numbers is 24, and their difference 8; what is the less number? 15. The sum of two numbers is 40, the less is 16; what is the greater? 16. A tree, 63 feet high, was broken off by the wind; the top part, which fell, was 49 feet long; how high was the stump which was left ? 17. Our pious ancestors landed at Plymouth, Massachusetts, in 1620; how many years since? 18. A man carried his produce to market; he sold his pork for 45 dollars, his cheese for 38 dollars, and his butter for 29 dollars; he received, in pay, salt to the value of 17 dollars, 10 dollars' worth of sugar, 5 dollars' worth of molasses, and the rest in money; bow much money did he receive? Ans. 80 dollars. 19. A boy bought a sled for 28 cents, and gave 14 cents to have it repaired; he sold it for 40 cents; did he gain or lose by the bargain? and how much? 20. One man travels 67 miles in a day, another man follows at the rate of 42 miles a day; if they both start from the same place at the same time, how far will they be apart at the close of the first day? of the third? fourth? of the second? of the 21. One man starts from Boston Monday morning, and travels at the rate of 40 miles a day; another starts from the same place Tuesday morning, and follows on at the rate of 70 miles a day; how far are they apart Tuesday night? Ans. 10 miles. 22. A man, owing 379 dollars, paid at one time 47 dollars, at another time 84 dollars, at another time 23 dollars, and at another time 143 dollars; how much did he then owe? Ans. 82 dollars. 23. A man has property to the amount of 34764 dollars, but there are demands against him to the amount of 14297 dollars; how many dollars will be left after the payment of his debts? 24. Four men bought a lot of land for 482 dollars; the first man paid 274 dollars, the second inan 194 dollars less than the first, and the third man 20 dollars less than the second; how much did the second, the third, and the fourth man pay? Ans. The second paid so. The third paid 60. 25. A man, having 10,000 dollars, gave away 9 dollars; how many had he left? Ans. 9991. MULTIPLICATION OF SIMPLE NUMBERS. T 9. 1. If one orange costs 5 cents, how many cents must I give for 2 oranges? how many cents for 3 oranges? for 4 oranges? 2. One bushel of apples costs 20 cents; how many cents must I give for 2 bushels? -for 3 bushels? 3. One gallon contains 4 quarts; how many quarts in 2 gallons? in 3 gallons? in 4 gallons? 4. Three men bought a horse; each man paid 23 dollars for his share; how many dollars did the horse cost them? 5. Á man has 4 farms worth 324 dollars each; how many dollars are they all worth? 6. In one dollar there are one hundred cents; how many cents in 5 dollars? 7. How much will 4 pair of shoes cost at 2 dollars a pair? 8. How much will two pounds of tea cost at 43 cents a pound? 9. There are 24 hours in one day; how many hours in 2 days? in 7 days? in 4 days? in 3 days? 10. Six boys met a beggar, and gave him 15 cents each; how many cents did the beggar receive? When questions occur, (as in the above examples,) where the same number is to be added to itself several times, the operation may he much facilitated by a rule called Multiplication, in which the number to be repeated is called the multiplicand, and the number which shows how many times the multiplicand is to be repeated is called the multiplier. The multiplicand and multiplier, when spoken of collectively, are called the factors, (producers,) and the answer is called the product. 11. There is an orchard in which there are 5 rows of trees, and 27 trees in each row; how many trees in the orchard? If we have learned that 7 taken 5 times amounts to 35, and that 2 taken 5 times amounts to 10, it is plain we feed write the number Multiplicand, 27 trees in each row. 27 but once, and then, setting the multiplier under it, we may say, 5 times 7 are 35, writing down the 5, and reserving the 3 (tens) as in addition. Again, 5 times 2 which we reserved, make 13, 10. 12. There are on a board 3 rows of spots, and 4 spots in each row; how many spots on the board? **** A slight inspection of the figure will show, that the number of spots inay be found either by taking 4 three times, (3 times 4 are 12,) or by taking 3 four times, (4 times 3 are 12;) for we may say there are 3 rows of 4 spots each, or 4 rows of 3 spots each; therefore, we may use either of the given numbers for a multiplier, as best suits our convenience. We generally write the numbers as in subtraction, the larger uppermost, with units under units, tens under tens, &c. Thus, **** Multiplicand, 4 spots. Product, 12 Ans. Note. 4 and 3 are the factors, which produce the product 12. Hence, Multiplication is a short way of performing many addi tions; in other words,-It is the method of repeating any number any given number of times. = SIGN. Two short lines, crossing each other in the form of the letter X, are the sign of multiplication. Thus, 3 X 4 that three times 4 are equal to 12, or 4 times 3 are 12. 12, signifies Note. Before any progress can be made in this rule, the following table must be committed perfectly to memory. |