Difficulty: Rating: GCSE Marks:

GCSE Text:
A fruit cake is baked with the following dimensions:

a) Calculate the volume of the cake

Fruit cake has a density of 1.22g/cm³

b) Calculate the weight of the cake

Suggestions:
This video is a festive example of a cooking calculation, but one that requires students to recall and understand the relationship between volume, mass and density.  This problem works well as a consolidation task and normally only takes students 4 – 5 minutes to solve. Discussions normally follow regarding the difference between mass and weight. Yes, we use M for mass in the calculation, but on the surface of the earth with a gravity of 1G, weight is the same as mass.  The extension works particularly well in challenging students who find this straight forward.

Extension Ideas:
Teachers could extend the learning by considering:

• A different cylindrical cake tin is used to make a cake of the same mixture but in a different shape. The cake weighs 2.7kg and is 4cm high. What is the diameter of the cake in cm (to 2 d.p.)?