GCSE Maths: Percentages
Practise GCSE Maths percentages including percentage change, reverse percentages and compound interest. Full AQA, Edexcel, OCR and Eduqas coverage.
What you need to know
The concepts examiners test on percentages, and what each one is really asking.
Where marks get lost
The exam technique that separates a correct method from a correct answer.
- Use multipliers for percentage change (e.g. 20% increase → × 1.2)
- For reverse percentages, divide by the multiplier
- Compound interest formula: A = P(1 + r/100)ⁿ
Percentages questions students ask
What is a multiplier in percentage calculations?
A multiplier is the decimal you multiply by to apply a percentage change. A 20% increase uses multiplier 1.2; a 15% decrease uses multiplier 0.85.
How do I work out a reverse percentage?
If you know a value after a percentage change, divide by the multiplier. E.g. after a 25% increase gives £75, the original was 75 ÷ 1.25 = £60.
What is compound interest?
Compound interest means interest is calculated on both the original amount and the accumulated interest. Use A = P(1 + r/100)ⁿ where P is principal, r is rate, n is number of years.