There is a square earth pit, and if it is dug down to a depth of 2 meters, its surface area will increase by 64 square meters and become a cuboid earth pit. What is the volume of the cuboid pit in cubic meters?
有一个正方体土坑，向下再挖深2米，它的表面积就增加64平方米，成为一个长方体土坑．这个长方体土坑的容积是多少立方米．
<gadget id="calculator">64 / 4</gadget>
<output>16</output>

<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">8 + 2</gadget>
<output>10</output>

<gadget id="calculator">8 * 8 * 10</gadget>
<output>640</output>

<result>640</result>