The PIER Method:
- Problem - What type of percentage problem is this?
- Identify - What's the original amount and what's the percentage?
- Execute - Apply the correct formula or method
- Review - Does your answer make sense in context?
Key Techniques:
- Multiplier Method: Increase by 15% → multiply by 1.15
- Decrease by 30% → multiply by 0.7
- Reverse Percentages: If £84 is after 20% VAT, original = £84 ÷ 1.2 = £70
- Multiple Changes: Apply each percentage change step by step
This deep dive covers Universal Percentage Problem Method within Percentage Problems for GCSE Mathematics. Revise Percentage Problems in Number for GCSE Mathematics with 14 exam-style questions and 22 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 3 of 8 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Percentage Problems
What is the multiplier for a 30% increase?
Work out 20% of 60.
Quick recall flashcards
What is the formula for simple interest?
I = PRT/100
where P = Principal, R = Rate (%), T = Time (years)
A £60 item has 25% off. What do you pay?
Method 1: Discount = £60 × 0.25 = £15, Pay = £60 - £15 = £45
Method 2: Pay = £60 × 0.75 = £45
Answer: £45