A 4-meter-long square steel is placed flat on the ground. When it is cut into 3 sections, the surface area increases by 80cm**2. What is the original volume of the square steel?
一根4米长的方钢平放在地面上，把它横截成3段时，表面积增加80cm**2，原来方钢的体积是多少．
<gadget id="calculator">80 / 4</gadget>
<output>20</output>

<gadget id="calculator">4 * 100</gadget>
<output>400</output>

<gadget id="calculator">20 * 400</gadget>
<output>8_000</output>

<result>8_000</result>