This deep dive covers Higher Level: Compound Percentages within Percentages for GCSE Mathematics. Revise Percentages in Number for GCSE Mathematics with 14 exam-style questions and 22 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 12 of 15 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 12 of 15
Practice
14 questions
Recall
22 flashcards
Higher Level: Compound Percentages
Multiple percentage changes:
- NOT additive: 10% increase then 10% decrease ≠ 0% change
- Multiply multipliers: +10% then -10% = 1.1 × 0.9 = 0.99 = -1%
- Order doesn't matter: +20% then +30% = ×1.2 ×1.3 = ×1.56 = +56%
Example: Price increases 20%, then decreases 15%
Overall multiplier = 1.2 × 0.85 = 1.02 = +2% overall