Chapter 9 · Questions · page 48 of 68
How do you find a percent of a number?
Short answerChange the percent to a decimal by dividing by 100, then multiply. 30% of 70 is 0.3 × 70, which is 21.
levelPre-algebra
standard6.RP.A.3c
practiceDecimals and percents
Percent means per hundred, and "of" means multiply. So a percent of a number is that many hundredths of it. For round percents there are shortcuts: 10% moves the decimal point one place left, 50% is half.
How to use it
- Divide the percent by 100 to get a decimal.
- Multiply the decimal by the number.
- Sense check: under 100% should give less than the number.
Example
Where it goes wrong
- Multiplying by 30 instead of 0.3.
- Dividing the number by the percent.