5% is 1/20

1/20 is 5% because half of 10% is 5% and half of 1/10 is 1/20

5*20=100.

By Jim Olsen, W.I.U.#P22

15%

20

100%

1

20

2 1

20 10

21

2020

20

4 1

20 5

3

20

0%5%

10%15%

20%105%

Find the percent

1. 7 out of 20 is what percent?

2. 30 = ___% of 200

30 315%

200 20

77 5% 35%

20

Recall the strategy:To find A% of BYou can change the percent to a fraction,Find B divided by the bottom, thenMultiply by the top.

Find 15% of $40

3 4015% of 40 40 3 2 3 6

20 20

Find the number

1. Find 5% of 180.

2. Find 105% of 80.

3. Find 65% of 400.

1 of 180 (180 20) 9

20

1105% of 80 100% of 80 + 80 80 4 84

20

13 40065% of 400= of 400 *13 20*13 260

20 20

Examples:

1. If 5% of the students played a sport and there are 12,000 students, how many played a sport?

2. The bag of dog food has 15% more FREE. Normally the bag has 40 lbs. How much is in the bag with the special offer?

3. If the restaurant bill is$42.60 and you want to tip 15%, what is the tip?

115% of 40 100% of 40 15% of 40 40 6 46 pounds

10% of 42.60 5% of 42.60

4.26 2.13

$6.39

1 12,000 of 12,000 600

20 20

Closing Notes

Remember

5% is 1/20To find 5% of a number divide by 20.

(or divide by 10 and then by 2)

#P22

Recap Fraction Percent

1/2 50 %

1/3 33⅓ %

1/4 25 %

1/5 20 %

1/6 16⅔ %

1/7 14 % *

1/8 12½ %

1/9 11% *

1/10 10 %

1/20 5 %* approximate

Here are the percents we know: