Percents and Decimals
The word percent means “hundredths” or “divided by 100.” The symbol % is used to represent percent.
39% means 39 divided by 100 or 
To convert a percentage to a decimal, remove the percent sign and divide by 100. (You can achieve the same result by moving the decimal point two places to the left.)
16.2% = 0.162
25 % = 0.25
To convert a decimal to a percentage, multiply by 100 and add the decimal point. (You can achieve the same result by moving the decimal point two places to the right.)
0.065 = 6.5%
3.75 = 375%
To find a percentage of a number, multiply the number by the decimal equivalent of the percent.
Example 1:
What is 30% of 40?
(0.30)(40) = 12
12 is 30% of 40.
To find what percent one number is of another, divide and convert the answer to the equivalent percent.
Example 2:
3 is what percent of 4?
3 ÷ 4 = 0.75 = 75%
3 is 75% of 4.
To find a number that is a certain percentage of another number, divide the number by the decimal equivalent of the percentage.
Example 3:
3 is 15% of what number?
3 ÷ 0.15 = 20
3 is 15% of 20.
To change a fraction into a percentage, divide to find its decimal equivalent and then change the decimal to the percentage.
15/20 = 0.75 = 75%
