To find a percentage of a number, enter the number
Multiply by the percent as a decimal
Convert the percent by dividing by 100
Example: 25% of 80 = 80 × 0.25 = 20
To find what percent one number is of another, divide the part by the whole
Multiply the result by 100
Example: 15 ÷ 60 = 0.25, then 0.25 × 100 = 25%
To increase a number by a percent, enter the number
Multiply by 1 plus the decimal percent
Example: 50 increased by 10% = 50 × 1.10 = 55
To decrease a number by a percent, enter the number
Multiply by 1 minus the decimal percent
Example: 50 decreased by 10% = 50 × 0.90 = 45
Use the percent key on the calculator if available
Enter the number, then the percent, then press the percent key if your calculator supports it
Check the calculator display for the result before continuing