Best buy
- Find unit price for each option.
- Compare the unit prices.
- Choose the lower price for better value.
Answer: £6 for 3 kg is £2/kg
⚖️ Ratio, Proportion & Rates
Best buys
Learn best buys with a GCSE-style explanation, help guide, worked example, practice question and flashcards.
Global XP
Level 10 / 100 XP
1. Explanation
Key idea
- Best buys is part of ratio & proportion and appears often in KS3–GCSE maths.
- Best buys compare equivalent unit costs.
- Use the worked model, help guide, interactive question and flashcards to practise best buys until the steps feel automatic.
Real-life examples
- Shopping, sport, travel, science, design and everyday decisions all use this skill.
2. Visual
Best buys 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 Best buys
- Learn the rule: Best buys compare equivalent unit costs.
- Worked model: Find unit price for each option. Compare the unit prices. Choose the lower price for better value.
- 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
Which is better value: 4 pens for £3.20 or 5 pens for £4.50?
6. Flashcards
Master quick recall
Flip each card, then choose whether you know it or need more practice.
0 mastered
FrontRule for Best buys
BackBest buys compare equivalent unit costs.
FrontExample answer: Which is better value: 4 pens for £3.20 or 5 pens for £4.50?
Back£3.20 ÷ 4 = £0.80 per pen. £4.50 ÷ 5 = £0.90 per pen. £0.80 is cheaper.
FrontCommon check for Best buys
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.