# Percent

Pronunciation: /pərˈsɛnt/ Explain

Percent is a ratio meaning for every 100 parts. The symbol for percent is '%'. 50% means 50 parts out of 100 parts, or 50 / 100 = 0.5.

### How to convert a ratio to a percentage

To convert a ratio to percentage, divide the numerator by the denominator, then multiply by 100 and add the percent sign.

Example 1: There are 20 students in a classroom. 9 of the students are girls. What percentage of the students are girls?

StepDescriptionCalculation
1Find the ratio. Since 9 out of 20 students are girls, the ratio is 9 / 20.9 / 20
2Divide the ratio.9 / 20 = 0.45
3Multiply by 100. 0.45 · 100 = 45
Table 1: Convert a ratio to a percentage example 1

Example 2: There are 250 students in a school. 100 students prefer strawberry ice cream over vanilla ice cream. What percentage of students prefer strawberry ice cream?

StepDescriptionCalculation
1Find the ratio. Since 100 out of 250 students prefer strawberry ice cream, the ratio is 100 / 250.100 / 250
2Divide the ratio.100 / 250 = 0.4
3Multiply by 100.0.4 · 100 = 40
Table 2: Convert a ratio to a percentage example 2

### How to convert a percentage to a ratio

To convert a percentage to a ratio, remove the percent sign, divide the percentage by 100, then multiply by the total population. You may need to round the result to the nearest whole number.

Example 3: If 27% of voters voted for Jamathan Johnson and there were 64 voters, how many people voted for Jamathan Johnson?

StepDescriptionCalculation
1Remove the percent sign.27% becomes 27.
2Divide the percentage by 100. 27 / 100 = 0.27.
3Multiply by the total population. 0.27 · 364 = 98.28.
4Round to the nearest whole number. 98.28 rounded to the nearest whole number is 98.
598 of 367 voters voted for Jamathan Johnson.98 / 367.
Table 3: Convert a percentage to a ratio

1. McAdams, David E.. All Math Words Dictionary, percent. 2nd Classroom edition 20150108-4799968. pg 136. Life is a Story Problem LLC. January 8, 2015. Buy the book