A 4-meter-long log is cut into 3 small logs, and the surface area increases by 8 square decimeters. What is the original volume of the log in cubic decimeters?
把一根4米长的圆木截成3段小圆木，表面积增加了8平方分米，这根圆木原来的体积是多少立方分米
<gadget id="calculator">8 / 4</gadget>
<output>2</output>

<gadget id="calculator">2 * 4 * 10</gadget>
<output>80</output>

<result>80</result>