Cube Net Folding

What these questions ask

There are a few variations on a theme here, but most present you with a net and five cubes, all viewed at a single corner. You are then asked which one of the cubes could be formed by the given net.

The question is therefore testing a student’s ability to visualise how the net comes together, from which faces meet to how their designs will be oriented.

How to tackle them

This is the protocol I teach my students:

1. Eliminate ‘duds’, or any cubes with faces that don’t appear on the net.
2. Eliminate opposites that appear to be touching. If a face is opposite another on the net, it will remain opposite on the folded cube.
3. Look at pointers, or faces which have a clear direction. If an arrow is pointing at a specific face, it must always point at that face. If it’s pointing away from another, this must also remain consistent.

These three can eliminate all but one answer in the lion’s share of problems.

And if that fails?

We then can look at which edges meet. If there’s a right angle between two faces on the net, the edges forming that right angle will touch. This can help us to identify which face goes where.

Also, look at groups of three. If face A is on top, face B is on the front, and face C is on the right of those two, it cannot teleport to the left.

Where it comes up

Cube nets appear in non-verbal reasoning portions of independent school entrance papers, the ISEB Pre-Test, and in GL-style 11+ assessments.

The format varies, but the skills required remain constant.

How to use this tool

Choose a net from the list; these can be reflected to give all possible cube nets. Then, customise the faces. There’s a limited arsenal of common patterns, but there is also the ability to draw your own faces.

Then click ‘Fold’, and the cube will come together. You can also:

• Mark the opposite faces on the net;
• Mark which edges will touch when the net is folded.

A note on when to use it

I always encourage students to attempt a question on their own before reaching for the tool, because these tools can solve problems without much effort. You aren’t learning how to solve the problem if you just observe the tool think for you.