A piece of rectangular iron sheet with a length of 8 decimeters and a width of 7 decimeters can be welded into a cuboid water tank without a cover after cutting a square with a side length of 2 decimeters from each of the four corners. What is the volume of this water tank in liters ?
一块长方形铁皮，长8分米，宽7分米，从四个角上各剪下一个边长2分米的正方形后，可以焊接成一个无盖的长方体水箱吗，这个水箱的容积是多少升？
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">8 - 4</gadget>
<output>4</output>

<gadget id="calculator">7 - 4</gadget>
<output>3</output>

<gadget id="calculator">4 * 3 * 2</gadget>
<output>24</output>

<result>24</result>