If a cube fish tank with a side length of 2 decimeters is filled with water, and then water is poured into a cuboid fish tank with a length of 5 decimeters and a width of 4 decimeters, what is the height of the water surface from the mouth of the tank?
如果在棱长2分米的正方体鱼缸内灌满水，然后将水再倒入长5分米，宽4分米的长方体鱼缸，这时水面离缸口的高是多少分米．
<gadget id="calculator">2 * 2 * 2</gadget>
<output>8</output>

<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">8 / 20</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>