Understanding Percent
When exchanging information, businesses need a way to express quantities using a common
unit of measure. Very often, this common unit of measure is the percent. For example, percent
can be used represent relationships among incomes of different years or account
classifications.
Percent is a notation based on 100, which makes it very convenient for use in business and
industry. The word “percent” comes from the Latin word “percentum” which means by the
hundred or per hundred. In fact, percent is defined as a fraction whose denominator is exactly
100.
Study the following examples showing three types of percent: whole number, decimal, and
fraction.
Given Meaning
15% 15
100
5.4% 5.4
100
1
% ½
2
100
93
100 93%
0.025 0.025%
100
2/3 2
%
3
100
Changing Decimal to Percent
To change decimal to percent, follow these steps.
Step 1. Change the decimal to a fraction with a denominator of 100.
Step 2. Change the fraction t percent by replacing per hundred by the percent sign (%)
Example 1: Change 0.36 to percent
Solution:
Step 1. Change the decimal to a fraction with a denominator of 100.
100 0.36 𝑥 100 36
0.36 x 100 = = 100
100
Step 2. Change the fraction to percent by replacing per hundred by the percent sign (%)
100 0.36 𝑥 100 36
0.36 x 100 = 100
= 100 = 36%
5
Example 2: Change 0.76 to percent
Solution:
5
5 7
6
Step 1. Rename 0.7 6 = 10
Step 2. Change the decimal to a fraction with a denominator of 100.
5 47 47 470 1
5 76 6 6
𝑥 10 6
783
0.7 = = = = =
6 10 10 10 𝑥 10 100 100
Step 3. Change the fraction to percent by replacing per hundred by % sign because the
denominator of 100 means by hundred or per hundred or percent.
5 47 47 470 1
5 7 𝑥 10 78 1
6 6 6 6 3
0.7 = = = = = = 78 %
6 10 10 10 𝑥 10 100 100 3
5 1
Thus, 0.7 = 78 %
6 3
Changing Fractions to Percent
To change fractions to percent, first change the fraction to decimal, and then change the
decimal to percent.
Example 3. Change 3/8 to percent.
Solution:
Step 1. Change the fraction to decimal.
3 1
= 0.375 or 0.37 2
8
Step 2. Change decimal to percent
3 100 0.375 𝑥 100 37.5 1
= 0.375 = 0.375 x 100 = = = 37.5% or 37 2 %
8 100 100
Thus, 3/8 = 37.5% or 37 1/2%
Alternate solution:
Multiply the fraction by 100 and put the percent sign.
3 3 3 𝑥 100 75
= ( 8 x 100) % = ( )%= % = 37.5% = 37 ½%
8 8 2
Changing Percent to Decimal
To change percent to decimal, replace the percent by a fraction bar over a denominator of
100. Then, simply divide by 100, which means that all you have to do is to move the decimal
point two places to the left.
Example 4. Change 37% to decimal.
Solution:
Step 1. Delete the percent sign and divide by 100
37
37% = = 0.37
100
Thus, 37% = 0.37
7
Example 5: Change 478 % to decimal
Solution:
Step 1. Delete the percent sign and divide by 100.
7
7 47 7 7 7
8
478 % = = 0.478 Thus, 478 % = 0.478
100
Changing Percent to Fraction
To change percent to fraction, replace the percent sign by a denominator of 100 and reduce
the fraction to lowest term.
Example 6. Change 34% to fraction
Solution:
Step 1. Replace the percent sign by a denominator of 100.
34
34% = 100
Step 2. Reduce the fraction to lowest term.
34 17
34% = = 50
100
1
Example 7. Change 92% to fraction.
Solution:
Step 1. Replace the percent sign by a denominator of 100.
1 19
1 92 2 19 1 19
9 = = = x =
2 100 100 2 100 100
Step 2. Reduce the fraction to lowest term, if possible.
1 19
1 92 2 19 1 19
9 = = = x =
2 100 100 2 100 200
1 19
Thus, 9 % =
2 200
