If a 5-meter-long log is cut into three small logs, the surface area increases by 8 square decimeters, what is the volume of this log in cubic decimeters?
把一根5米长的圆木截成三段小圆木，表面积增加了8平方分米，这根圆木的体积是多少立方分米．
<gadget id="calculator">8 / 4</gadget>
<output>2</output>

<gadget id="calculator">5 * 10</gadget>
<output>50</output>

<gadget id="calculator">2 * 50</gadget>
<output>100</output>

<result>100</result>