rectangular iron sheet with a width of 16 cm is cut off at its four corners to form a square with a side length of 4 cm, and then it is welded into a rectangular box without a cover. If the volume of this box is 768 cubic centimeters, then this What is the original area of the iron sheet in square centimeters?
一块宽是16厘米的长方形铁皮，在它的四个角分别剪去边长是4厘米的正方形，然后把它焊接成一个无盖的长方体盒子，如果这个盒子的容积是768立方厘米，那么这块铁皮原来的面积是多少平方厘米？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

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

<gadget id="calculator">4 * 8</gadget>
<output>32</output>

<gadget id="calculator">768 / 32</gadget>
<output>24</output>

<gadget id="calculator">24 + 8</gadget>
<output>32</output>

<gadget id="calculator">32 * 16</gadget>
<output>512</output>

<result>512</result>