1. Percent Proportion

2. Percent
Means ‘of a hundred’

3. The Percent Proportion(s)
You will use a proportion to solve most percent problems.
Remember: the percent will always be related to a hundred.

4. The Percent Proportion(s)
‘of’ is the number with the word ‘of’
‘is’ is the number with the word ‘is’ is %
The percent % is always over 100.
100 is always on the bottom. = of
100
This proportion can be used when dealing with simple percent statements such as:
“What is 10% of 100?”
“10 is what percent of 100?”
“10 is 10% of what number?”

5. Cross multiply to get the answer.
50 is what percent of 230? is of %
100 =
Use the proportion. 50 x = or
x = 21.7%
50 is 21.7% of 230
230
100
Cross multiply to get the answer.

6. Cross multiply to get the answer.
What is 85% of 40? is of %
100 =
Use the proportion. x 85 = 40
100
x = 34
34 is 85% of 40
Cross multiply to get the answer.

7. Cross multiply to get the answer.
25% of what number is 400? is of %
100 =
Use the proportion.
400 25 = x
100
x = 1600
25% of 1600 is 400
Cross multiply to get the answer.

8. Cross multiply to get the answer.
What is 175% of 80? is of %
100 =
Use the proportion. x
175 = 80
100
Cross multiply to get the answer.
x = 140
140 is 175% of 80

9. 19 is 25% of what number?
What percent of 256 is 64?
What is 45% of 178?

10. Cross multiply to get the answer.
19 is 25% of what number? is of %
100 =
Use the proportion. 19 25 = x
100
Cross multiply to get the answer.
x = 76
19 is 25% of 76

11. Cross multiply to get the answer.
What percent of 256 is 64? is of %
100 =
Use the proportion. 64 x =
256
100
Cross multiply to get the answer.
x = 25%
25% of 256 is 64

12. Cross multiply to get the answer.
What is 45% of 178? is of %
100 =
Use the proportion. x 45 =
178
100
Cross multiply to get the answer.
x = 80.1
80.1 is 45% of 178

13. Word Problems