A cube glass tank with a side length of 4dm is filled with water, and then all the water is poured into a rectangular tank with a bottom area of 20dm**2. How many decimeters is the water surface in the tank? (Solve using equation method)
一个正方体玻璃缸，棱长4dm，用它装满水，再把水全部倒入一个底面积为20dm**2的长方形水槽中，槽里的水面高多少分米？(用方程的方法解答)
<gadget id="calculator">4 * 4 * 4</gadget>
<output>64</output>

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

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