The Multiplier Method Explained
Part of Percentage Decrease · GCSE GCSE Mathematics revision
This deep dive covers The Multiplier Method Explained 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 3 of 6 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 3 of 6
Practice
12 questions
Recall
22 flashcards
📊 The Multiplier Method Explained
Step-by-Step Process
- Identify the percentage decrease
- Convert to decimal: percentage ÷ 100
- Subtract from 1: 1 - decimal = multiplier
- Multiply original by multiplier
Why Subtract from 1?
When we decrease by 25%, we want:
- Original amount (100%) - Removed amount (25%) = 75%
- 75% = 0.75 as a decimal
- So multiplier = 1 - 0.25 = 0.75
Common Multipliers
| Decrease | Multiplier | Calculation |
|---|---|---|
| 5% | 0.95 | 1 - 0.05 |
| 10% | 0.90 | 1 - 0.10 |
| 15% | 0.85 | 1 - 0.15 |
| 20% | 0.80 | 1 - 0.20 |
| 25% | 0.75 | 1 - 0.25 |
| 30% | 0.70 | 1 - 0.30 |
Keep building this topic
Read this section alongside the surrounding pages in Percentage Decrease. That gives you the full topic sequence instead of a single isolated revision point.
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
12 questions on Percentage Decrease — practise free
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