Cut a rectangular iron sheet with a length of 40 cm and a width of 30 cm and cut off a square with a length of 4 cm to make a rectangular box without a cover. What is the volume of this box (the thickness of the iron sheet is not counted)
把一块长为40厘米，宽为30厘米的长方形铁皮的四角各剪去一个变长为4厘米的正方形做成一个无盖的长方体盒子，这个盒子的容积是多少(铁皮厚度不计)
<gadget id="calculator">40 - 4 - 4</gadget>
<output>32</output>

<gadget id="calculator">30 - 4 - 4</gadget>
<output>22</output>

<gadget id="calculator">32 * 22 * 4</gadget>
<output>2_816</output>

<result>2_816</result>