A cylindrical wooden stick is 4 meters long. If it is cut into two sections, the surface area will increase by 12.56 square decimeters compared to the original one. Find the volume of this wooden stick.
一根圆柱形木棍长4米，如果把它截成2段，表面积比原来增加了12.56平方分米，求这根木棍的体积．
<gadget id="calculator">12.56 / 2</gadget>
<output>6.28</output>

<gadget id="calculator">4 * 10</gadget>
<output>40</output>

<gadget id="calculator">6.28 * 40</gadget>
<output>251.2</output>

<result>251.2</result>