A cylinder of wood is 2 meters long. If its height is reduced by 2 decimeters, its surface area will be reduced by 25.12 square decimeters. What is the volume of this wood?
一根圆柱体木头长2米，若把它的高减少2分米，它的表面积就减少25.12平方分米，这根木头的体积是多少？
<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 * 10</gadget>
<output>251.2</output>

<result>251.2</result>