cylinder of wood with a length of 4 meters is averagely cut into two sections, and the surface area increases by 25.12 square decimeters. What is the volume of this wood in cubic decimeters?
一根长4米的圆柱体木料，把它平均截成2段后表面积增加了25.12平方分米，原来这根木料的体积是多少立方分米．
<gadget id="calculator">25.12 / 2</gadget>
<output>12.56</output>

<gadget id="calculator">10 / 10</gadget>
<output>1</output>

<gadget id="calculator">12.56 * 4 * 1</gadget>
<output>50.24</output>

<result>50.24</result>