Percent as a Decimal

A percent is a number of hundredths, so it turns into a decimal by dividing by 100: move the point two places left. 45% becomes 0.45, 8% becomes 0.08, and 150% becomes 1.5.

That gives a quick way to find a percent of a number. 45% of 80 is 0.45 × 80. Multiply as you learned for decimals: 45 times 80 is 3600, and the two decimal places of 0.45 put the point back two places, so the answer is 36.

Watch the small percents. 8% has only one digit, so it needs a zero to fill the tenths place: 0.08, not 0.8. Reading 0.8 aloud as 80 hundredths shows why: that would be 80%.