This problem is solved by sawing these cubic blocks of the same size into eight blocks of the same size. For example, the side length of the original cube building blocks is 10 cm, and the surface area of each building block is10x10x6 = 600 (square cm); After sawing into a small cube with a length of 5 cm, the surface area is 5×5×6×8= 1200 (square cm). The surface area has doubled.