If a 2.5dm long cylindrical wood is cut off by 2dm, the surface area is reduced by 25.12d㎡, what is the original volume of this wood in cubic decimeters?
把一根2.5dm长的圆柱形木料截去2dm，表面积比原来减少了25.12d㎡，这根木料原来的体积是多少立方分米？
<gadget id="calculator">25.12 / 2 / 3.14 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">3.14 * 4 * 2.5</gadget>
<output>31.4</output>

<result>31.4</result>