Problem: What fraction of each grid is shaded?
Each grid above has 100 boxes. For each grid, the ratio of the number of shaded boxes to the total number of boxes can be represented as a fraction.
Comparing Shaded Boxes to Total Boxes 
Grid 
Ratio 
Fraction 
1 
96 to 100 

2 
9 to 100 

3 
77 to 100 

We can represent these fractions as percents using the symbol %.
Definition: A percent is a ratio whose second term is 100. Percent means parts per hundred. The word comes from the Latin phrase per centum, which means per hundred. In mathematics, we use the symbol % for percent.
Let's look at our comparison table again. This time the table includes percents.
Comparing Shaded Boxes to Total Boxes 
Grid 
Ratio 
Fraction 
Percent 
1 
96 to 100 

96% 
2 
09 to 100 

09% 
3 
77 to 100 

77% 
Let's look at some examples in which we are asked to convert between ratios, fractions, decimals and percents.
Example 1: Write each ratio as a fraction, a decimal, and a percent: 4 to 100, 63 to 100, 17 to 100
Solution 
Ratio 
Fraction 
Decimal 
Percent 
04 to 100 

.04 
04% 
63 to 100 

.63 
63% 
17 to 100 

.17 
17% 
Example 2: Write each percent as a ratio, a fraction in lowest terms, and a decimal: 24%, 5%, 12.5%
Solution 
Percent 
Ratio 
Fraction 
Decimal 
24% 
24 to 100 

.240 
05% 
05 to 100 

.050 
12.5% 
12.5 to 100 

.125 
Example 3: Write each percent as a decimal: 91.2%, 4.9%, 86.75%
Solution 
Percent 
Decimal 
91.2% 
.9120 
04.9% 
.0490 
86.75% 
.8675 
Summary: A percent is a ratio whose second term is 100. Percent means parts per hundred and we use the symbol % to represent it. In this lesson, we learned how to convert between ratios, fractions, decimals and percents.
Exercises
Directions: Read each question below. Select your answer by clicking on its button. Feedback to your answer is provided in the RESULTS BOX. If you make a mistake, choose a different button.
1. Which of the following is equal to ?


2. Which of the following is equal to 21.8%?


3. Which of the following is equal to 150%


4. Which of the following is equal to .0179?


5. Which of the following is equal to 56.28%?

