rectangular iron sheet with a width of 16 cm is cut off from its four corners to 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 780 cubic centimeters, the original What is the area of the iron sheet in square centimeters?
一块宽是16厘米的长方形铁皮，在它的四角上分别剪去边长是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780立方厘米，原来这块铁皮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">780 / 32</gadget>
<output>195/8 = around 24.375</output>

<gadget id="calculator">(195/8) + 8</gadget>
<output>259/8 = around 32.375</output>

<gadget id="calculator">(259/8) * 16</gadget>
<output>518</output>

<result>518</result>