Ratio & ProportionDeep Dive

Method: Finding the Best Buy

Part of Best Buy — GCSE Mathematics

This deep dive covers Method: Finding the Best Buy within Best Buy for GCSE Mathematics. Revise Best Buy 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 7 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 7

Practice

12 questions

Recall

22 flashcards

Method: Finding the Best Buy

1 Identify what you're comparing (per kg, per litre, per item)

2 Calculate price per unit for each option

3 Compare - lowest price per unit = best buy

4 Check for special offers (3 for 2, BOGOF, discounts)

Keep building this topic

Read this section alongside the surrounding pages in Best Buy. That gives you the full topic sequence instead of a single isolated revision point.

Key Methods for Best Buy Worked Example 1: Basic Price Per Unit What Is a Best Buy?Worked Example 2: Multi-Buy Offer

Practice Questions for Best Buy

Which method correctly compares the value of two products?

A. Compare the total prices
B. Compare the cost per unit (e.g. cost per gram)
C. Choose the one with the larger pack size
D. Choose the one with the smaller pack size

1 markfoundation

Three sizes of shampoo are available: - Travel: 100 ml for 95p - Regular: 300 ml for £2.55 - Family: 500 ml for £4.00 Find the best value size. Show all working.

3 marksstandard

Quick Recall Flashcards

What does BOGOF mean?

Buy One Get One Free. You pay for 1 item but get 2 items. Price per item = Normal price ÷ 2.

What does 'best buy' mean?

The option that gives the lowest cost per unit (per gram, per litre, per item). Calculate by dividing total price by quantity.

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Key Methods for Best Buy

Worked Example 1: Basic Price Per Unit