A piece of steel with a length of 4 meters and a square cross section is cut into two pieces, and the surface area increases by 64 square centimeters. What is the original volume of this piece of steel?
一根长4米，横截面是正方形的钢材，截成两段后，表面积增加了64平方厘米，原来这根钢材的体积是多少？
<gadget id="calculator">64 / 2</gadget>
<output>32</output>

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

<gadget id="calculator">32 * 400</gadget>
<output>12_800</output>

<result>12_800</result>