A cube water tank with a side length of 4 meters is filled with water. If this tank of water is poured into a water tank with a length of 4 meters and a width of 2.5 meters, how deep is the water in meters?
一个棱长是4米的正方体水箱，装满了水，若把这箱水倒入一个长4m，宽2.5m的水箱中，水有多少米深？
<gadget id="calculator">4 * 2.5</gadget>
<output>10</output>

<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">4 * 4 * (2/5)</gadget>
<output>32/5 = around 6.4</output>

<result>32/5 = around 6.4</result>