The volume of this stack is 214 cubic inches. The volume of the bottom box is equal to 150 cubic inches, because the formula for volume is length x width x height. The top box is a cube, which means all edges have an equal size. If one edge measures 4 inches, then the length, width, and height of the cube are all 4 inches. 4 x 4 x 4, or 4 to the power of 3, or 4 cubed, is equal to 64 cubic inches. 150 cubic inches added to 64 cubic inches is 214 cubic inches. The volume of the stack is equal to 214 cubic inches.