Page images
PDF
EPUB
[blocks in formation]

15. What is the difference between 91 and 23.

[blocks in formation]

RULE.

To

1068

SOLUTION. - We first reduce the fractional parts, and, to a common denominator, 12. Since we cannot take from, we add 1 = to, which makes 19, and 11⁄2 from 11⁄2 leaves. We now add 1 to the 2 in the subtrahend (50). Three from 9 leaves 6. We thus obtain 62, the difference required.

subtract mixed numbers, reduce the frac

tional parts to a common denominator, and then subtract the fractional and integral parts separately. Or,

Reduce the mixed numbers to improper fractions, and subtract the less from the greater by the usual method.

[blocks in formation]

22. Find the difference between 49 and 751.

23. Find the difference between 2275 and 1963. 24. From a cask of oil containing 31 gallons, 17 gallons were drawn. How many gallons remained? Ans. 137. 25. A farmer, having 4507 acres of land, sold 3043 How many acres had he left? Ans. 14518. 26. If flour is bought for $61 per barrel, and sold for $74, what will be the gain per barrel?

acres.

84

27. From the sum of 5 and 31⁄2, take the difference between 4 and 51. Ans. 325. 28. What number added to 25 will make 74 ? Ans. 425. 29. What fraction added to 11 will make 18? Ans.

MULTIPLICATION.

EXAMPLES.

135. To multiply a fraction by an integer.

1. If 1 yard of cloth costs of a dollar, how much will 5 yards cost?

OPERATION.

1 × 5 = 45 = 33, Ans. fourths, equal to 33 dollars. ing its numerator (124).

SOLUTION. - Since 1 yard costs 3

fourths of a dollar, 5 yards will cost 5 times 3 fourths of a dollar, or 15 A fraction is multiplied by multiply

2. If 1 gallon of molasses costs of a dollar, how much will 5 gallons cost?

OPERATION.

2 × 5=1=14, Ans.

[blocks in formation]

is a factor of 20, the denominator of the multiplicand, we perform the mul tiplication by dividing the denominator, 20, by the multiplier, 5, and we have, equal to 12 dollars. A fraction is multiplied by dividing its denominator (124).

RULE.

To multiply a fraction multiply its numerator,

or divide its denominator.

Always divide the denominator when it is exactly divisible by the multiplier.

[blocks in formation]

8. Multiply 73 by 12. 9. Multiply 81 by 8. 10. Multiply by 51. 11. Multiply 15% by 16.

12. Multiply 101 by 22.

Ans. 91. Ans. 54

Ans. 2.

Ans. 250.

Ans. 168.

13. If a man earns $8% a week, how many dollars will he earn in 12 weeks?

14.

What will 9 yards of silk cost at of a dollar per yard?

15. What will 27 bushels of barley cost at 7 of a dollar per bushel? Ans. $235.

136. To multiply an integer by a fraction.

1. At $75 an acre, how much will of an acre of land

[merged small][merged small][merged small][ocr errors][merged small][merged small]

Multiplying by a fraction consists in multiplying by the numerator and dividing by the denominator of the multiplier.

[blocks in formation]

159, Ans.

Or, 65=53.

= 159.

53

24 ×

=

8

[ocr errors][merged small][merged small][merged small][merged small]

7. Multiply 42 by 93.
8. Multiply 80 by 149.

9. Multiply 156 by 7.

Ans. 409.

Ans. 1165.

Ans. 108.

19. At $8 a bushel, what will of a bushel of clover seed cost?

11. If a man travels 36 miles a day, how many miles will he travel in 10 days? Ans. 384 miles. 12. If a village lot is worth 450 dollars, what is of it worth? Ans. 262 dollars. 13. At 16 dollars a ton, what is the cost of 23 tons of hay?

137. To multiply a fraction by a fraction.

1. At of a dollar per bushel, how much will & of a bushel of corn cost?

[merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

SOLUTION.-Dividing of a dollar by 4, we have, the cost of of a bushel. A fraction is divided by multiplying its denominator (124). Multiplying the cost of of a bushel by 3, we have

of a dollar, the cost of of a bushel. It will readily be seen that we have found the product of the two numerators, 2 and 3, for a new numerator, and of the two denominators, 3 and 4, for a new denominator.

RULE. I. Reduce all integers and mixed numbers to improper fractions.

II. Find the product of the numerators for a new numerator, and of the denominators for a new denominator.

Cancel all factors common to numerators and denominators.

2. Multiply by 4.

3. Multiply by .

4. Multiply

by 8.

5. Multiply 4

by 4.

Ans.. Ans. Ans. 3

Ans. 38.

6. What is the product of, 4, 5, and 1?
7. What is the product of 15, 3, 2, and 51?

[merged small][merged small][merged small][merged small][ocr errors][ocr errors]

SOLUTION.

[ocr errors]

10

[ocr errors]

X X

OPERATION.

7

[ocr errors]

X

[ocr errors]

3

8

47

X

Ans. 18 Ans. 111}. times of of 7,

8 7

=

5 30'

Ans.

Canceling like factors in the numerators and denominators, we have left in the numerator 7, and in the denominator 5 × 6 = 30, making for the product.

Fractions with the word of between them are sometimes called compound fractions. The word of is simply an equivalent for the sign of multiplication, x.

[blocks in formation]

11. What is the sum of the products of 3, 4 of 4, and

[blocks in formation]

of of 3

times

Ans. 254

of 9?

15. What is the product of 121 multiplied by 51⁄2 times

63 ?

Ans. 46416

16. At of a dollar per yard, what will g of a yard of cloth cost? Ans. of a dollar. 17. If a man owns of a vessel, and sells of his share, what part of the whole vessel will he sell?

18. When oats are worth

of a dollar per bushel,

what is of a bushel worth ? 19. What will 73 pounds of tea cost, at of a dollar per pound? Ans. $418.

20. What will 5 yards of cloth cost at of a dollar a yard? Ans. $3.

21. If a man owns of a plot of ground and sells of his share, what part of the plot does he sell?

« PreviousContinue »