1. Math 015 Section 8.1 Percents

2. Obj: To write a percent as a fraction or a decimal
Percent means parts of 100
In the figure at the right, 23 of the 100 squares are shaded.
We say that 23% of the squares are shaded.
In most application problems it will be necessary to convert percents to fractions or decimals in order to work with them in the problems.

3. Obj: To write a percent as a fraction or a decimal
1. remove the percent sign
2. divide by 100
3. simplify the fraction
Examples: change the following percents to fractions 13
13% = =
100 44
44% = =
100

4. Obj: To write a percent as a fraction or a decimal
1. remove the percent sign
2. divide by 100
3. simplify the fraction
Examples: change the following percents to fractions
240 12 25
240% = = = 2
100 5 1 23 16 23 = 50 16
16 % = = 3
100 2

5. Certain percents and their fraction equivalents should be memorized
1 5
20 %
25 %
50 %
75 % =
1 6 23 % % % =
1 4
1 3 13
1 2
2 3 23
3 4

6. Obj: To write a percent as a fraction or a decimal
To write a percent as a decimal
1. remove the percent sign
2. divide by 100
Examples: change the following percents to decimals
61 % = 61
100 =
0.61
0.5 % =
0.5
100 =
0.005
235 % =
235
100 =
2.35

7. Obj: To write a fraction or a decimal as a percent
To write a fraction or decimal as a percent
1. multiply by 100 %
Examples: change the following to percents 38 38
100 %
300 75 12 = = % = % =
37 % 8 2
0.048 =
0.048
100 % =
4.8 %
1.17 =
1.17
100 % =
117 %

8. 1 Obj: To write a fraction or a decimal as a percent
To write a fraction or decimal as a percent
1. multiply by 100 %
Write as a percent: write the remainder in fraction form 56 56
100 %
500
250 % 13 = = % = =
83 % 6 3
Write as a percent: round to the nearest tenth 13
100 %
1300 1 49 = = % =
144.4 % 9 9