MathBrush

The pattern

Seeing it move

Work out where the pieces land after a fold, cut or stack.

Seeing it move illustrated in pencil.
The key insight from Net of a cube — the opposite face, drawn in pencil.
The key step, from Net of a cube — the opposite face
ABCDEFa straight strip of three: the two ends land opposite

A shape gets folded, cut or rearranged, and the answer comes from tracking where each piece lands rather than from a formula. A fold reflects one part onto another, so an angle either side of the crease survives unchanged. A strip of three squares folded into a cube always sends the two ends to opposite faces.

How to spot it

Words like 'folded', 'cut along the dotted line' or 'stacked' appear beside a shape, and the question asks for a length or angle that only makes sense once the pieces are in their new positions.

Common mistake

Children try to calculate the answer before working out where the pieces actually end up, skipping the visualisation step that the whole question depends on.

47 worked solutions

Standard

Challenging

All the problem patterns → · the revision list

The 33 problem patterns

All 33 patterns, one to a page — the 19 behind Primary 5 and 6 word problems, and the skills the younger years are built on. The bar model, how to spot it in the question, and the mistake children make. A booklet you can print. Free.

A PDF, and a note when new solutions go up.