Volume is counting cubes: one layer of length × width, stacked height times. This lesson builds the l × w × h formula from that picture and fixes the cm²-vs-cm³ confusion for good.
The bottom layer holds length × width cubes: 5 × 3 = 15.
The height says how many layers stack up: 4.
15 × 4 = 60 cubes → 60 cm³.
A toy box is 40 cm long, 30 cm wide and 20 cm tall. Find its volume.
Wrong! That’s one layer (area). Multiply by the height too: 5 × 3 × 4 = 60 cm³.
Wrong! Volume counts cubes: cm³. (cm² is area — flat squares.)
Relax! Multiplication order doesn’t matter — all orders give 60. Pick the easiest pairing.
Length × width × height. A 5 × 3 × 4 cm box holds 60 cm³.
Because it counts how many 1 cm × 1 cm × 1 cm cubes fit inside — cubes, not flat squares.
Counting cubes starts in Year 5; using l × w × h (including cm³ and m³) is a Year 6 objective in England.
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