Why do this problem?
leads on from Building with Cubes
by introducing larger numbers of cubes so that there is more information to be kept in your mind's 'eye' at one time. Being able to visualise is a useful skill which learners are often not used to drawing on. By explicitly talking about
visualisation, and offering opportunities like this for your class to practise visualising, you will be encouraging them to use this skill in their independent problem solving.
This activity might also be a good context in which to introduce isometric paper to your class. Recording on this paper is a skill in itself, but it is extremely useful for drawing 3D images of cubes.
It would be a good idea for the class to try Building with Cubes
before they tackle this problem, including having a go at the introductory activities described in that problem's notes.
Can you see those two cubes in your head?
What about the third one?
If it is under/behind/ on the right of that one, where will it be?
As you picture each stage in your head, can you to draw it so that you can keep track of where the cubes are?
Tell me about the building in your head.
Learners could try, Green Cube, Yellow Cube
Suggest staying with Building with Cubes