Ratio & ProportionDiagram

Worked Examples

Part of Percentage DecreaseGCSE Mathematics

This diagram covers Worked Examples within Percentage Decrease for GCSE Mathematics. Revise Percentage Decrease 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 4 of 5 in this topic. Focus on the labels, the relationships between parts, and the explanation that turns the diagram into an exam-ready answer.

Topic position

Section 4 of 5

Practice

12 questions

Recall

22 flashcards

🎯 Worked Examples

Example 1: Shop Discount

Problem: A laptop costs £800 with a 25% discount. What's the sale price?

Step 1: Identify the decrease = 25%

Step 2: Convert to decimal = 25 ÷ 100 = 0.25

Step 3: Find multiplier = 1 - 0.25 = 0.75

Step 4: Sale price = £800 × 0.75 = £600

Example 2: Car Depreciation

Problem: A car worth £12,000 depreciates by 18% in one year. What's its new value?

Step 1: Decrease = 18%

Step 2: Decimal = 0.18

Step 3: Multiplier = 1 - 0.18 = 0.82

Step 4: New value = £12,000 × 0.82 = £9,840

Example 3: Population Decline

Problem: A village has 2,500 residents. Population decreases by 12%. How many residents remain?

Step 1: Decline = 12%

Step 2: Decimal = 0.12

Step 3: Multiplier = 1 - 0.12 = 0.88

Step 4: Remaining population = 2,500 × 0.88 = 2,200

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. 0.35
  • B. 0.65
  • C. 1.35
  • D. 1.65
1 markfoundation

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.

2 markshigher

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

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