The diameter of the base of a cylinder is 10dm, and the height is 8dm. If it is divided into several equal parts and assembled into approximate cuboids, how much is the surface area increased by cubic meters?
一个圆柱的底面直径是10dm，高是8dm，把它平均分成若干等份，拼成近似的长方体，表面积增加了多少立分方米．
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">8 * 5 * 2</gadget>
<output>80</output>

<result>80</result>