Each unit cube contains a cubic unit of volume and each of the surfaces of the cubes are a square unit of area. A rectangular prism that is two cubes wide, one cube long and four cubes tall will have a volume of 8 units3 and a surface area of 28 units2. A composite cube that is two cubes wide, two cubes long and two cubes high will have the same volume of 8 units3 but a surface area of only 24 units2.