This key facts covers Key Facts: Percentage Decrease within Percentage Decrease for GCSE Mathematics. Revise Percentage Decrease in Ratio & Proportion for GCSE Mathematics with 12 exam-style questions and 22 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 2 of 6 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
🔑 Key Facts: Percentage Decrease
- Percentage decrease = finding a new amount after subtracting a percentage
- Multiplier method = 1 - (percentage ÷ 100)
- New amount = Original amount × Multiplier
- Common examples: discounts, depreciation, population decline, weight loss
- Multiplier < 1 always (because we're taking away from the original)
Practice questions for Percentage Decrease
What multiplier is used to decrease a value by 35%?
A shop advertises '25% off everything'. A student says: 'The multiplier is 0.25 because 25% = 0.25.' Explain what is wrong with the student's reasoning and state the correct multiplier.
Quick recall flashcards
What is the multiplier for a 10% decrease?
0.90 (because 1 - 0.10 = 0.90)
What is a percentage decrease?
Finding a new amount after subtracting a percentage from the original amount