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Everyday maths 2 (Wales)
Everyday maths 2 (Wales)

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9.2 Changing a fraction to a percentage

There are two ways you can do this.

Method 1

To change a fraction into a percentage, multiply it by 100 divided by one (essentially, you are just multiplying the top number by 100 and the bottom number will stay the same).

Example: Change three divided by four into a percentage

three divided by four × 100 divided by one = 300 divided by four

This cancels to 75 divided by one = 75%

Note: Remember anything over 1 is a whole number. If you do not end up with a 1 on the bottom, you will have to divide the top number by the bottom one to get your final answer.

Method 2

Divide the top of the fraction by the bottom (to express the fraction as a decimal) and then multiply the answer by 100.

Example: three divided by four = 3 ÷ 4 = 0.75

Described image
Figure 12 Expressed as a decimal: 3 ÷ 4
  • 0.75 × 100 = 75%

Activity 22: Changing a fraction to a percentage

  1. Express these fractions as percentages:

    • a.three divided by eight


    • b.nine divided by 10


    • c.four divided by five



    • a.37.5%

    • b.90%

    • c.80%

Now you’ll look at changing a fraction to a decimal.