If a piece of cuboid wood is shortened by 5 decimeters, its surface area is reduced by 120 square decimeters and becomes a cube. What was the original volume of the piece of wood in cubic decimeters?
一段长方体木材，如果锯短5分米，它的表面积就减少120平方分米，且变成一个正方体．这段木材原来的体积是多少立方分米？
<gadget id="calculator">120 / 5 / 4</gadget>
<output>6</output>

<gadget id="calculator">6 + 5</gadget>
<output>11</output>

<gadget id="calculator">6 * 6 * 11</gadget>
<output>396</output>

<result>396</result>