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2192                                                                 ARITHMETIC

I.   To find a given per cent of a number.

A.   Find 16% of $1250. B.  Find 75% of $1600.

$1250,                                       $1600 X 3

.16                                        '--4-- = $1^00.

7500 1250

$200.00

Rule. To find a per cent of a given number, multiply the given number by the rate per cent expressed either decimally or as a common fraction. Always use the shorter method.

EXERCISE 31.

1.   Find   24% of $2846. 5.   Find   33^% of $1866.

2.   Find   35% of $4850. 6.   Find 200 % of $854.50.

3.   Find   60% of $1500. 7'.   Find 0.25 % of $4000.

4.   Find 420% of $6480. 8.   Find 0.33 J% of $9612.

9.  A farmer having 450 sheep lost 8%. How many had he left!

A.     450 = no, of sheep                       B.        450 = no. of sheep

.08                                                        .92

36.00 = no. lost                                        900

414 = no. left                                   4050

414.00 = no. left

Method B is preferable. If he loses 8% of his sheep, he must have 92% left.

Much drill is desirable along this line that the pupil may at once recognize the per cent to be used as a multiplier.

10.   A school numbers 580 children; 45% are boys. How many girls are there!

11.   A man's income is $1850 a year. He spends 82% of it. How much does he save?

12.   A farmer raised 3840 bu. of grain, and sold 68% of it. How much did he sell?

13.   I had $2480 and spent 24% of it. How much had I left!

14.   A house was bought for $6440, and sold at a gain of 22%. What was the selling price!