If a cuboid lumber with a length of 80 cm, a width of 5 cm, and a height of 5 cm is sawn into two sections with a length of 40 cm, how much the surface area increases compared to the original one.
把一根长80厘米、宽5厘米、高5厘米的长方体木材，锯成长度都是40厘米的两段，表面积比原来增加了多少．
<gadget id="calculator">5 * 5 * 2</gadget>
<output>50</output>

<result>50</result>