Hold up (or show) a 4 × 3 × 2 multilink box. Take three hands-up guesses, not open call-outs. Do not count yet — the point is that some cubes are hidden inside, so guessing is hard. That tension is what the lesson resolves.

• 4 × 3 × 2 — bottom layer is 4 × 3 = 12 cubes; two layers, so 24 cm³. This is the box from the hook — reveal the answer to the guesses now.
• 8 × 4 × 3 — bottom layer 32 cubes, three layers, 96 cm³. Point to the bottom layer on screen and count 8 × 4 = 32 aloud before revealing the height, so the leap from counting every cube to layer × height is shown, not only said. Then ask: why don't we count every cube one by one any more?
• 5 × 5 × 5 — the cube; base 25, five layers, 125 cm³. Hold out for a pupil to notice all three dimensions are equal.

Every readout carries cm³ — point to the little 3 and say the units matter.

This is a whole-class board activity: one pupil at a time comes up to set the sliders on the single shape-measurer while the rest watch and call out the bottom layer and the layer count together. Re-set the same interactive's length, width and height sliders for each of the three targets in order. Three slider-and-read reveals with class prediction fill the ten minutes.

Before each reveal, ask the class to work out the bottom layer and the layer count. 3 × 2 × 2 = 12 cm³; 4 × 4 × 4 = 64 cm³; 10 × 10 × 10 = 1000 cm³. Stop on the last one: a box 10 cm on every side holds exactly a litre of water. That link back to capacity is the key one — hold out for a pupil to remember 1000 ml = 1 l.

Hand out the tubs of multilink cubes before this step. This is the practice round — pupils build at their own desks and one pupil brings each build to the board to check it against the shape-measurer set to the same dimensions; the class confirms before moving on. Keep it brisk.

If cubes are not available, run it as a whole-class board activity: read out each target, the class predicts a length, width and height, and you (or a pupil) set the shape-measurer to check.

• 12 cm³ — e.g. 3 × 2 × 2, or 6 × 2 × 1, or 12 × 1 × 1.
• 24 cm³ — e.g. 4 × 3 × 2, or 6 × 4 × 1.
• 36 cm³ — e.g. 6 × 3 × 2, or 9 × 4 × 1.
• Stretch: 24 cm³ with the biggest base means a single flat layer — a 24 × 1 × 1 or 12 × 2 × 1 box. Draw out that the same volume can have many shapes.

Look for pupils who realise there is more than one right answer for each target.