Relating volume to the operations of multiplication and addition (5.MD.C.5)

Find the volume of a right rectangular prism with whole-number side lengths by packing it with unit cubes, and show that the volume is the same as would be found by multiplying the edge lengths, equivalently by multiplying the height by the area of the base. Apply the formulas V=lwh and V=bh for rectangular prisms to find volumes of right rectangular prisms. Recognize volume as additive.