A piece of cuboid wood is 2 meters long. After cutting it into three sections, the surface area increases by 4 square decimeters. What is the original volume of the piece of cuboid wood in cubic decimeters?
一段长方体木材长2米，把它横截成三段后，表面积增加了4平方分米，这段长方体木材原来的体积是多少立方分米．
<gadget id="calculator">4 / 4</gadget>
<output>1</output>

<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">1 * 20</gadget>
<output>20</output>

<result>20</result>