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 cm^{3} which is 1 000 000
cm^{3} a million cubic centimetres. The volume of sand in the lorry
is about 2 x 4 x 0.5 cubic metres, which is 4 m^{3}.
