Step-by-Step Process
- Identify the percentage increase
- Convert to decimal: percentage ÷ 100
- Add to 1: 1 + decimal = multiplier
- Multiply original by multiplier
Why Add 1?
When we increase by 15%, we want:
- Original amount (100%) + Extra amount (15%) = 115%
- 115% = 1.15 as a decimal
- So multiplier = 1 + 0.15 = 1.15
Common Multipliers
| Increase | Multiplier | Calculation |
|---|---|---|
| 5% | 1.05 | 1 + 0.05 |
| 10% | 1.10 | 1 + 0.10 |
| 15% | 1.15 | 1 + 0.15 |
| 20% | 1.20 | 1 + 0.20 |
| 25% | 1.25 | 1 + 0.25 |
| 50% | 1.50 | 1 + 0.50 |
This deep dive covers The Multiplier Method Explained within Percentage Increase for GCSE Mathematics. Revise Percentage Increase in Ratio & Proportion for GCSE Mathematics with 12 exam-style questions and 22 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. 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.
Practice questions for Percentage Increase
What multiplier is used to increase a value by 15%?
Ahmed says: 'To increase a price by 30%, I first find 30% of the price and then add it on. This always takes two steps.' Explain how Ahmed could use the multiplier method to find the answer in ONE step.
Quick recall flashcards
What is a percentage increase?
Finding a new amount after adding a percentage to the original amount
What is the multiplier for a 10% increase?
1.10 (because 1 + 0.10 = 1.10)