A cylindrical wood with a length of 5 decimeters is split in half along its diameter, and the surface area increases by 40 square decimeters. What is the volume of the original wood in cubic decimeters?
将一根长5分米的圆柱形木料，沿着直径纵劈成两半，表面积增加了40平方分米，原来木料的体积是多少立方分米．
<gadget id="calculator">40 / 2 / 5</gadget>
<output>4</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 5</gadget>
<output>62.8</output>

<result>62.8</result>