1. Exercise
Write 24% as a decimal.
0.24

2. Exercise
Write 157% as a decimal.
1.57

3. Exercise
1 2
Write % as a decimal.
0.255

4. Exercise
Solve the proportion.
x 20
15 100 =
x = 3

5. Exercise
Solve the proportion.
x 150
50 100 =
x = 75

6. Percent Formula
The percent of the whole is equal to the part: percent x whole = part.

7. Example 1 Find 5% of $115 by the formula method. 5% = 0.05
percent × whole = part
0.05(115) = part
$5.75 = part

8. Proportion Method
The part is to the whole as the percent is to 100:
part
whole
percent
100 = .

9. Example 2 Find 104% of 250 by the proportion method. part whole =
percent 100
part 250 =
100(part) = 250(104)
100(part) = 26,000
part = 260

10. Example 3
Mr. Ward decided that he would give an additional 2 % above his tithe, or % total. Find % of $4,500.
1 2
1 2
1 2
12 %
1 2
= 12.5%
= 0.125
0.125 x 4,500 = part
$ = part

11. Example 4 What percent of 12 is 16? percent x whole = part p x 12 = 16

12. Example 4 What percent of 12 is 16? 1.33 12 16.00 1 3 p = 1.33 12 40
1.33 12 40 36 4
p = 1.33
1 3
p = %
1 3

13. Example 5
108 is what percent of 150? Solve by using a proportion. Round to the nearest tenth. =
p 100
150p = 10,800
150
p = 72
108 is 72% of 150.

14. Example 6
Eight is 16% of a number. Find the number by using the formula.
0.16 x w = 8
0.16w = 8
0.16
w = 50
The whole amount is 50.

15. Example 7 28% of what number is 182? Solve by using a proportion.=
28 100
28w = 18,200 28
w = 650
The whole amount is 650.

16. Forms of the % equation:
percent x whole = part
part
whole
percent =
percent
part
whole =

17. Example
Find 30% of 69.
20.7

18. Example
30% of what number is 69?
230

19. Example
24 is what percent of 48?
50%

20. Example
96 is what percent of 48?
200%

21. Example
17 is what percent of 34?
50%

22. Example
0.03 is what percent of 300?
0.01%

23. Example
What percent on a test is a score of 62 out of 80?
77.5%

24. Example
If the standard tip at a restaurant is 15%, how much was the total, including tip, on a bill of $46? (This question is equivalent to the question “what is 115% of 46?”)
$52.90

25. Example
It is recommended that no more than 12% of one month’s income go toward a car payment. How much of a car payment can someone afford on an income of $2,720 a month?
$326.40

26. Example
Certain people believe it is difficult for a church to grow after reaching 90% of capacity because people don’t want to feel crowded. If a church can hold 600 people, how many people can comfortably attend the church without feeling crowded?
540