GCSE Maths Practice: best-value

Question 10 of 10

Soap bars are sold in different pack sizes. Compare the cost per bar to decide which offer the best value.

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\( \begin{array}{l} \text{Which soap bar packs give the best value for money?} \end{array} \)

Select all correct options:

If the unit price is the same, all options are equally good value.

Best Value with Equal Unit Prices

In many GCSE Maths best value questions, students expect there to be one clear answer. However, real-life pricing does not always work this way. Sometimes products are priced proportionally, meaning that no matter which pack you choose, you pay the same amount for each individual item.

This question is designed to check whether you truly understand the idea of unit price rather than relying on guesswork. When all options have the same cost per item, they all offer equal value for money.

The Cost Per Item Method

When products are sold in packs containing different numbers of items, the fairest way to compare value is to calculate the cost per item.

  1. Count how many items are in each pack.
  2. Divide the total price by the number of items.
  3. Compare the unit costs.

If the unit costs are identical, then no option is better or worse than the others.

Worked Example

A shop sells bars of chocolate in the following packs:

  • 2 bars for £1.20
  • 5 bars for £3.00
  • 10 bars for £6.00

Calculate the cost per bar:

  • £1.20 ÷ 2 = £0.60 per bar
  • £3.00 ÷ 5 = £0.60 per bar
  • £6.00 ÷ 10 = £0.60 per bar

Each pack costs the same per bar, so all options give equal value.

Another Example

A stationery shop sells erasers as:

  • 3 erasers for £0.90
  • 6 erasers for £1.80
  • 9 erasers for £2.70

Dividing the price by the number of erasers shows that each eraser costs the same amount.

Common Mistakes

  • Assuming bigger packs are better: A larger pack does not always offer better value.
  • Choosing only one answer: If unit prices match, more than one answer may be correct.
  • Skipping calculations: Always calculate the unit cost, even if prices look proportional.

Real-Life Applications

Retailers often price products so that different pack sizes offer the same value. This allows customers to choose based on convenience, storage space, or usage needs rather than price. Understanding this helps you avoid overthinking and recognise when there is no financial advantage to buying a particular size.

This skill is useful when comparing household items, toiletries, food packs, and bulk purchases.

Frequently Asked Questions

Can all options really be correct?
Yes. If the unit price is the same for all options, they all offer equal value.

How do I check for equal value?
Calculate the cost per item for each option and compare.

Does this appear in GCSE exams?
Yes. Foundation papers sometimes include questions where multiple answers are correct.

Study Tip

If all unit prices match, trust your calculations — equal unit cost means equal value.

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