Convert the percent to a decimal by dividing by 100
Multiply the decimal by the whole amount
Use the formula: part = percent × whole
To find what percent one number is of another, divide the part by the whole
Multiply the result by 100
Use the formula: percent = part ÷ whole × 100
To find the whole when you know the part and percent, divide the part by the decimal percent
Use the formula: whole = part ÷ decimal percent
To find a percentage increase, subtract the old value from the new value
Divide the difference by the old value
Multiply by 100
To find a percentage decrease, subtract the new value from the old value
Divide the difference by the old value
Multiply by 100
To find 10%, move the decimal one place left
To find 1%, divide by 100
To find 5%, find 10% and divide by 2
To find 25%, divide by 4
To find 50%, divide by 2
To find 75%, find 50% and add 25%