Kitchen Clock
Three short lessons on the maths of a dinner: working backward from the meal with one oven, why a roast twice as heavy takes less than twice as long, and what a kilo of carrots really costs once it is trimmed.
For grown-ups, from what SaffronLab teaches children at Spark & Anvil.
- Lesson 1Work backward from the meal
- Lesson 2Why a big roast takes less than twice as long
- Lesson 3What a kilo really costs
The one-oven dinner on paper
You'll need: Strips of paper, a pen, a ruler or a long table edge as the clock.
- Write each dish on a strip, one centimetre for every ten minutes it needs, and mark the oven dishes.
- Lay the meal time at the right-hand end. Slide every strip so it ends there, then shuffle the oven strips so none of them overlap.
- Read off the earliest start. Ask: which strip could move without changing it, and which could not?
- Now add a dish and see whether the start moves. Talk about why it sometimes does not.
A little history, and what nobody knows
The standard cup
Fannie Farmer’s Boston Cooking-School Cook Book of 1896 helped to standardise the measurements used in cooking in the United States.
The source does not say how quickly home cooks took the new measures up.
Source: Fannie Farmer (Wikipedia)
The same idea, with the world taken away
Three jobs need the same tool, one after another, and all must be done by a fixed time. How do you find the latest moment you can start?
Ask it, then let everyone say the answer in their own words. A child's rung on Spark & Anvil ends the same way, with the world gone and the numbers left.
The same idea at every age
- Ages 3–5You Cut, a Friend Chooses
- Ages 6–8The Lost Cup and 1 more
- Ages 9–14Dinner at Six and 1 more
- Ages 15–18Baker’s Percentages and 1 more
Your child will meet this idea again at every age. The tools and courses here are the part for you.