This document provides steps for solving percent problems using proportions: 1. Write the percent as a fraction over 100 and identify the whole and part. 2. Set up a proportion between the percent fraction and the values given. 3. Solve the proportion to find the missing value. Percent problems can be solved by setting up and solving proportions between the percent as a fraction of 100 and the given values.

1. Solving Percents with Proportions
Shawana Melton
10/18/10
Cent: 100 cents in a dollar
Centipede: About 100 legs on a bug
Century: 100years
Centimeter: 100centimeters in a meter
Percent: per 100 or each 100
Write the following percents as fractions (do not
simplify):
43% =43/100 3.8% =3.8/100 112% = 112/100
87% =87/100 5% =5/100 300% = 300/100
Steps to solve percent problems:
1. Fill in the :
100
%
""
""
=
of
is
.
2. The proportion.
1. What is 45% of 80? 2. 8 is 12% of what number?
x=
______ ______
= x=
3. 24% of 32 is what number?
4. 110% of what number is 66?
______ ______
= x=
______ ______
= x=
Percent
Percent fraction
100
%
__"_"
_"__"
100
%
==
of
is
or
whole
part
45
100
x
80
12
100
8
x
24
100
x
32
110
100
66
x

2. 5. 18 is 60% of what number? 6. 40% of what number is 26?
______ ______
= x=
______ ______
= x=
7. What is 125% of 34? 8. 58% of 250 is what number?
______ ______
= x=
______ ______
= x=
Sometimes you will not know the percent.
Remember, the word “what” in a problem tells you it is
the variable.
9. What percent of 27 is 9? 10. 50 is what percent of 120?
______ ______
= x=33
______ ______
= x=41.6-
11. 74 is what percent of 70? 12. What percent of 8 is 16?
______ ______
= x=
______ ______
= x=
13. What is 25% of 30? 14. 25% of what number is 17?
______ ______
= x=
______ ______
= x=
15. 12 is 75% of what number? 16. 6 is what percent of 8?
______ ______
= x=
______ ______
= x=
What we did was percents and how to solve variable.
x
100
9
27
50
120
x
100
60
100
18
x
40
100
26
x
74
70
x
100
x
100
16
8
25
100
x
30
17
x
25
100
12
x
75
100
6
8
x
100