Real-life questions from the kitchen: scaling recipes up and down, how much of each ingredient and cooking times. Read the story, work it out and type the answer.
One cake needs 4 eggs. Lily bakes 3 cakes. How many eggs does Lily need?
Twice as many people: double every amount.
Half as many people: halve every amount.
Any other number: find the amount for 1 person, then multiply.
1000 g = 1 kg
Cooking times: add each part on, or work backwards from when it must be ready.
Time by weight: count the lots of 500 g (or 1 kg), multiply, then add any extra time.
A ratio of 1 : 4 means 1 part for every 4 parts, so 5 parts in all.
For twice as many people, double every amount; for half as many, halve it. For any other number, find the amount for 1 person first, then multiply. A recipe for 4 with 200 g of flour has 50 g a person, so 6 people need 6 × 50 g = 300 g.
Count how many lots of the weight there are, multiply by the time for each, then add any extra time. A 2 kg chicken at 20 minutes for every 500 g plus 20 minutes is 4 × 20 + 20 = 100 minutes, which is 1 hour 40 minutes.
Work backwards from when the food must be ready. Take away the cooking time, jumping back to the o'clock first. For dinner at 6:00 PM with 1 hour 15 minutes in the oven, the food goes in at 4:45 PM.
A ratio of 1 : 4 means 1 part of one thing for every 4 parts of the other, so 5 parts in all. For 500 mL of squash mixed 1 : 4, one part is 500 ÷ 5 = 100 mL: 100 mL of squash and 400 mL of water.