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GCSE Maths / Edexcel

Recipes and scaling

Scale recipe quantities up or down using a multiplier, one-portion method, or equivalent ratio.

Ratio, Proportion and RatesFoundation and HigherGrades 3 to 5Focused skill

Curriculum path: GCSE Maths > Edexcel > Ratio, Proportion and Rates > Recipes and scaling

Pearson Edexcel GCSE Maths ratio R10: solve direct proportion problems, including recipes and scaling.

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Revision notes

Theory, examples, and quick checks.

Keep the method short, then practise straight away. This note is written for GCSE Maths Edexcel students who need clear working and reliable method marks.

Theory

Recipe questions are direct proportion questions. If the number of portions doubles, each ingredient doubles.

Find the scale factor from old portions to new portions, then multiply every ingredient by that scale factor.

If the scale factor is awkward, find the amount for one portion first, then multiply by the new number of portions.

All ingredients must be scaled by the same multiplier. You cannot add the same amount to every ingredient.

For Edexcel marks, write the scale factor or one-portion line before the final ingredient amount.

Key ruleNew amount = old amount x (new portions / old portions).

Worked examples

Scale up

A recipe for 4 people uses 300 g of flour. How much flour is needed for 10 people?

  1. Scale factor = 10 / 4 = 2.5.
  2. 300 x 2.5 = 750.

Answer: 750 g

One-portion method

A recipe for 6 cakes uses 180 g sugar. How much sugar is needed for 15 cakes?

  1. One cake uses 180 / 6 = 30 g.
  2. 15 cakes use 15 x 30 = 450 g.

Answer: 450 g

Scale down

A recipe for 8 people uses 1.2 litres of milk. How much milk is needed for 2 people?

  1. 2 is one quarter of 8.
  2. 1.2 / 4 = 0.3.

Answer: 0.3 litres

Common mistakes

  • Adding the difference in portions to the ingredient amount.
  • Using a different multiplier for different ingredients.
  • Dividing when the recipe is being scaled up.
  • Forgetting to keep units such as grams, millilitres or litres.

Quick exercise

Try these before moving to the exam-style questions.

  1. A recipe for 4 uses 200 g flour. How much for 6?
  2. A recipe for 5 uses 150 g sugar. How much for 20?
  3. A recipe for 8 uses 400 ml milk. How much for 2?
  4. 12 cakes need 3 eggs. How many eggs for 20 cakes?
  5. A recipe for 3 uses 90 g butter. How much for 10?
Exam-style questions

Practise the same skill at three levels.

These are original GCSE-style questions with mark schemes, common wrong answers, and AI marking guidance so feedback stays close to exam expectations.

Basic GCSE styleFoundationCalculator3 marks

A recipe for 4 people uses 240 g of rice. Work out how much rice is needed for 7 people.

recipesdirect proportionfoundation ratio
Standard exam styleFoundation and HigherCalculator4 marks

A recipe for 6 muffins uses 150 g butter and 240 g flour. Work out the butter and flour needed for 15 muffins.

recipe scalingmultiple ingredientsproportion
ChallengeFoundation and HigherCalculator5 marks

A recipe for 12 biscuits uses 300 g flour. Sam has 875 g flour. What is the greatest number of biscuits Sam can make?

limiting ingredientrecipe proportionproblem solving