This exam tips covers Exam Success Strategies within Growth & Decay for GCSE Mathematics. Revise Growth & Decay in Number for GCSE Mathematics with 12 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 6 of 8 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 6 of 8
Practice
12 questions
Recall
22 flashcards
Exam Success Strategies
- Identify growth vs decay first: Look for keywords like "increases", "doubles", "grows" vs "decreases", "halves", "decays"
- Convert percentages carefully: 5% increase means multiply by 1.05, not 0.05
- Count time periods correctly: If something doubles every 2 hours over 8 hours, that's 4 periods, not 8
- Use special formulas for doubling/halving: N₀ × 2ⁿ for doubling, N₀ × (0.5)ⁿ for halving
- Check reasonableness: Growth should give bigger values, decay should give smaller values
- Round appropriately: Money to 2 dp, bacteria to whole numbers, percentages to 1 dp
- Watch units: Time periods must match the rate period (yearly rate needs years, not months)