If the height of a cuboid is reduced by a part, the rest becomes a cube with side length 5 cm, and the volume is reduced by 100 cubic centimeters, how much is the surface area of the cuboid reduced?
一个长方体，高减少一部分，剩下的就成为一个棱长5厘米的正方体，同时体积减少100立方厘米，这个长方体的表面积减少多少．
<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">100 / 25</gadget>
<output>4</output>

<gadget id="calculator">5 * 4 * 4</gadget>
<output>80</output>

<result>80</result>