The formula for finding the volume of a cube is
Length x Width x Height.
Since each side of a cube has the same measurement, the formula can also be stated "Side Cubed", or
Side x Side x Side.
Since the sides of the cube measure 4 inches, you would multiply to find the volume,
4 x 4 x 4,
which equals 64.
The answer when finding volume is always a cubic measurement.
The volume of a cube measuring 4 inches on all of its sides is 64 cubic inches.