Percentages

Percent change measures how much a value has increased or decreased relative to its original value, expressed as a percentage.

A percentage is a fraction out of 100. To find a percentage of a number, multiply the number by the percentage divided by 100.

Simple interest is calculated on the original principal only. The formula I = PRT links the interest, principal, rate, and time. Compound interest is briefly introduced as interest on interest.

VAT (Value Added Tax) is a percentage added to a price. Discounts are percentages subtracted from a price. Knowing how to calculate both is an essential everyday maths skill.