ratioProportion · Year 6 · Suggested learning sequence
Scaling recipes
Every serve of a recipe needs the same amount, so amounts scale by multiplying, never by adding. If the new number of serves is a multiple of the old one, multiply by that many. Otherwise use the unitary method: find the amount for one serve, then multiply by the serves you need. You can also find how many times bigger the new recipe is, such as 6 ÷ 4 = 1.5 times.
Sample questions
A smoothie recipe for 2 serves uses 40 mL of milk. How much milk is needed for 8 serves?
- 8 serves is 8 ÷ 2 = 4 times as many as 2 serves.
- 40 × 4 = 160.
- 160 mL of milk is needed.
Answer: 160
A pancake recipe for 2 serves uses 80 g of flour. How much flour is needed for 6 serves?
- 6 serves is 6 ÷ 2 = 3 times as many as 2 serves.
- 80 × 3 = 240.
- 240 g of flour is needed.
Answer: 240
A muffin recipe for 2 serves uses 50 g of sugar. How much sugar is needed for 6 serves?
- 6 serves is 6 ÷ 2 = 3 times as many as 2 serves.
- 50 × 3 = 150.
- 150 g of sugar is needed.
Answer: 150