NumberStudy Notes

Common Percentage Traps

Part of Percentage Problems · GCSE GCSE Mathematics revision

This study notes covers Common Percentage Traps 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 4 of 8 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 4 of 8

Practice

14 questions

Recall

22 flashcards

Common Percentage Traps

  • Adding VAT to VAT: Don't add 20% VAT to a price that already includes VAT
  • Double Discounts: 20% off then 10% off ≠ 30% off (it's actually 28% off)
  • Percentage vs Percentage Points: Interest rising from 3% to 5% is a 2 percentage point increase, not 2%
  • Base Confusion: Make sure you know what the percentage is OF
  • Reverse Calculation Errors: To remove 20% VAT, divide by 1.2, don't subtract 20%

Keep building this topic

Read this section alongside the surrounding pages in Percentage Problems. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Percentage Problems

What is the multiplier for a 30% increase?

  • A. 0.3
  • B. 0.7
  • C. 1.3
  • D. 1.03
1 markfoundation

Work out 20% of 60.

1 markfoundation

Quick Recall Flashcards

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
What is the formula for simple interest?
I = PRT/100 where P = Principal, R = Rate (%), T = Time (years)

14 questions on Percentage Problems — practise free

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