If a 4-meter-long cuboid steel is cut into two sections, the surface area increases by 10 square decimeters, what is the original volume of this steel?
把一根长4米的长方体钢材截成两段，表面积比原来增加了10平方分米，这根钢材原来体积是多少？
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">4 * 10</gadget>
<output>40</output>

<gadget id="calculator">5 * 40</gadget>
<output>200</output>

<result>200</result>