A cube fish tank, side length 4 decimeters. If a full tank of water is poured into another empty cuboid tank with a length of 8 decimeters and a width of 2.5 decimeters, find the height of the water surface in the tank.
一个正方体鱼缸，棱长4分米．如果把满缸水倒入另一个长8分米，宽2.5分米的长方体空水槽里，求槽中水面的高．
<gadget id="calculator">4 * 4 * 4</gadget>
<output>64</output>

<gadget id="calculator">8 * 2.5</gadget>
<output>20</output>

<gadget id="calculator">64 / 20</gadget>
<output>16/5 = around 3.2</output>

<result>16/5 = around 3.2</result>