Teacher notes

A 35-minute upper-primary lesson on nets and surface area.

1. 5 min: show a box and ask how many faces can be seen.
2. 10 min: predict fold lines and assemble the cube.
3. 10 min: measure faces and calculate total area.
4. 10 min: compare differently proportioned boxes and explain why equal volume can have unequal surface area.

For support, start with labelled faces. For extension, ask students to design a second valid cube net and justify it by folding.