Answer:

A Cubic metre is a unit for measuring volume. A cube whose edges are all 1 metre long has a volume of 1 cubic metre. Since 1 metre is 100 cm, the volume of such a cube is 100 x 100 x 100 cm³ which is 1 000 000 cm³ a million cubic centimetres. The volume of sand in the lorry is about 2 x 4 x 0.5 cubic metres, which is 4 m³.