A cuboid iron water tank has a length of 6dm, a width and a height of 4dm, and a water depth of 3.2dm. How many liters of water will overflow in the water tank after an iron block with a side length of 3dm is put into it?
一只长方体铁皮水箱，长6dm，宽和高为4dm，水深3.2dm，投入一个棱长3dm的铁块后，水箱里的水溢出多少升？
<gadget id="calculator">3 * 3 * 3</gadget>
<output>27</output>

<gadget id="calculator">6 * 4 * 3.2</gadget>
<output>76.8</output>

<gadget id="calculator">6 * 4 * 4</gadget>
<output>96</output>

<gadget id="calculator">76.8 - 96</gadget>
<output>-19.2</output>

<gadget id="calculator">27 + (-19.2)</gadget>
<output>7.8</output>

<result>7.8</result>