Simplify a ratio
- Find a common factor.
- Divide every part by it.
- Keep the order of the parts.
Answer: 15:20 = 3:4
⚖️ Ratio, Proportion & Rates
Ratio
Learn ratio with a GCSE-style explanation, help guide, worked example, practice question and flashcards.
Global XP
Level 10 / 100 XP
1. Explanation
Key idea
- Ratio is part of ratio & proportion and appears often in KS3–GCSE maths.
- Ratios compare parts and can be simplified like fractions.
- Use the worked model, help guide, interactive question and flashcards to practise ratio until the steps feel automatic.
Real-life examples
- Shopping, sport, travel, science, design and everyday decisions all use this skill.
2. Visual
Ratio learning map
Understand the key idea → follow the help guide → practise a question → check your method → build speed with flashcards.
3. Help guide
How to tackle Ratio
- Learn the rule: Ratios compare parts and can be simplified like fractions.
- Worked model: Find a common factor. Divide every part by it. Keep the order of the parts.
- Try the interactive question without looking at the answer first.
- Use the flashcards to test the rule, the method and a common check.
4. Worked examples
Step-by-step working
5. Interactive questions
Try it yourself
Simplify the ratio 12:18.
6. Flashcards
Master quick recall
Flip each card, then choose whether you know it or need more practice.
0 mastered
FrontRule for Ratio
BackRatios compare parts and can be simplified like fractions.
FrontExample answer: Simplify the ratio 12:18.
Back12 ÷ 6 = 2 and 18 ÷ 6 = 3, so 12:18 = 2:3.
FrontCommon check for Ratio
BackCheck units/notation, compare with an estimate, and make sure the answer matches the question.
7. Finish
Complete this topic
When you have read the examples, tried the question and reviewed flashcards, claim your topic completion XP.