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.
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?
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.