Writing Fractions as Percents
Not only can we express a percent as a fraction, but we can
express a fraction as a percent. To do this, recall that percent
means a ratio that compares a number to 100. So to convert a
fraction to a percent, we set up a proportion problem that
compares the given fraction to a fraction whose denominator is
100 but whose numerator is unknown.
Example 6
Express the fraction as a percent.
Solution
Step 1 Set up a proportion. Let x represent
the unknown numerator (the percent).
Step 2 Solve the proportion using cross
multiplication. 1
1 Â· 100 
= 4 Â· x 
Write the cross products. 
100 
= 4x 
Divide each side by 4. 
25 
= x 

So, is equivalent to 25%.
Example 2
Express the fraction as a percent.
Solution
Set up a proportion and solve it.


3 Â· 100 
= 5 Â· x 
300 
= 5x 
60 
= x 
So, is equivalent to 60%.
Try to work on several examples that use only fractions whose
denominators are factors of 100, such as 2, 4, 5, 20, and 25.
Then the resulting equivalent percent will be a whole number.
Computing with percents is an extremely important skill. Be
sure to work on several problems. This will help you solidify your
understanding of the concept of percent, as well as help with
your computational skills involving fractions.
