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'Toad in the Hole' printed from http://nrich.maths.org/

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Why do this problem?

This problem is one of a series on the maths required by the Food Technology curriculum.
In this particular problem, students are required to investigate whether it is more economical to make a Toad in the Hole from scratch or to buy a ready meal.
The answer to this will depend on the number of people to be fed - and also whether you view the ingredients not required for this particular meal as waste or simply as not required immediately (so for instance, you put them away for another time or make more than you need to freeze some for later).
Problems like this give students the opportunity to practise calculations involving proportions.

Possible approach

Students could start by discussing which they think would be more economical to prepare, and what other factors might influence their decision on whether to start from scratch or not - it would be great if someone from the Food Technology department could be part of this.
There are several ways in which the calculation might be approached - students could brainstorm how they might do it, and various methods be displayed so those who find it difficult to get started can choose a way that makes sense to them.

Key questions

If you know that 1 litre of vegetable oil costs £1.45, how can you calculate how much 15ml costs?  (And similar questions for the other ingredients).

What is a sensible way to round calculations, where necessary?

Possible extension

What difference does it make to the conclusion if the cost of cooking is also taken into account?  This will require students to find out how much it costs to heat an oven (could be gas or electric).  They will also need to investigate how long the Toad in the Hole needs to cook for, and at what temperature.

Possible support

Model the sort of calculations that students will need to do before giving them the problem to work on.