Skip to main content
MathidiaMathematics Academy
Compound measures
Lesson 9 of 9
Review

Best buys

Objective. Compare value for money using unit price.

  1. 1. Learn
  2. 2. Worked example
  3. 3. Practice
  4. 4. Feedback
  5. 5. Continue

Learn: the key idea

Convert every option to the same unit — price per 100 g or per litre — then the smallest number wins.

Worked example

500 g for £2.40 or 750 g for £3.45. Which is better?

Clock face showing 2 hours and 40 minutes
  1. 1£2.40 ÷ 5 = £0.48 per 100 g.
  2. 2£3.45 ÷ 7.5 = £0.46 per 100 g.
  3. 3£0.46 is less.

Answer: The 750 g pack

Concept mastery

Based on your past attempts at this lesson — the question types to practise again come first.

Complete a practice set to see your concept breakdown here.

Practice

Practice happens on its own screen, one question at a time. Answers stay hidden until you submit yours, and you can stop and pick up at the same question later.

Start practising

Common mistake. Assuming the bigger pack is always cheaper per unit.

Your progress

Tick each step as you finish it. Your exact reading position is saved automatically, so Continue drops you back on the same line.

0 of 5 steps complete

Your place saves automatically as you read.

My dashboard