8.1.3 Writing a Fraction as a Percentage

Using the same idea that multiplication by 100% means multiplication by 1, you can also convert fractions into percentages.

Example

three divided by 25 multiplication 100 percent equation left hand side equals right hand side open three divided by 25 multiplication 100 close percent equation left hand side equals right hand side open three divided by 21 times five multiplication one times zero times zero super four divided by one close percent equation left hand side equals right hand side open three multiplication four divided by one multiplication one close percent equals 12 percent

Pencast symbol

See this additional example turning a fraction into a percentage (click on “View document”).

View document [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)]

As an alternative, you can turn the fraction into a decimal first, and then move the decimal point:

Example: equation sequence seven divided by 20 equals 0.35 equals 35 percent.

Summary

To change a decimal or fraction to a percentage, multiply by 100%, or change to a decimal and then to percent.

There are other alternative ways, such as multiplying the numerator and denominator of the fraction to be converted by 100 divided by 100, shown in this example:

equation sequence two divided by five equals two multiplication 100 super 20 divided by five sub one multiplication 100 equals 40 divided by 100 equals 40 percent

For this last example, note that the fraction can be expanded by multiplication so that the denominator is turned into 100. For some fractions, this gives you another alternative for the conversion. For this last example, it looks like this:

equation sequence two divided by five equals two divided by five multiplication 20 divided by 20 equals 40 divided by 100 equals 40 percent

Pencast symbol

Let’s revisit the different ways in which you can convert decimals and fractions into percents (Click on “View document”).

View document

8.1.2 Writing a Decimal as a Percentage

8.1.4 The Importance of the Percent Sign