GCSE Maths: Growth & Decay
Calculate compound interest, depreciation, and repeated percentage change. Practise it with adaptive questions for AQA, Edexcel, OCR and Eduqas.
What you need to know
The concepts examiners test on growth & decay, and what each one is really asking.
Where marks get lost
The exam technique that separates a correct method from a correct answer.
- Calculating simple interest instead of compound (e.g. just adding 3% four times)
- Using the wrong multiplier for decay (e.g. using 1.20 for a 20% decrease instead of 0.80)
- Rounding the multiplier before doing the power calculation
- Forgetting to round money to 2 decimal places
Growth & Decay questions students ask
Is Growth & Decay on the Foundation paper?
Yes. Growth & Decay appears at both Foundation and Higher tier, though Higher papers take it further.
What should I know before starting Growth & Decay?
It builds on Percentages and Multipliers and Indices. If those feel shaky, practise them first — Growth & Decay questions assume them.
What is the most common mistake in Growth & Decay?
Calculating simple interest instead of compound (e.g. just adding 3% four times).
Which exam boards cover Growth & Decay?
All four we support — AQA, Edexcel, OCR and Eduqas. GCSE Maths subject content is set by the DfE, so the topic is common to every board; what changes is the paper structure and the grade boundaries.