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!