When we need the area of cube?

Answer 1

multiply size three times itself
width = height = depth
all the same as it is a cube

so 4cm cube = 4³ = 4 x 4 x 4
= 16 x 4 = 64
which is sixty-four cubic centimetres
as an example.

Answer 2

When we want to work out how much sheet material is required to make the cube or to work out the cost of coating (painting?) the sides of the cube.