A cuboid glass fish tank is 50 cm long, 40 cm wide, and 30 cm high. Inject 40 liters of water into an empty fish tank, how deep is the water?
一个长方体玻璃鱼缸长50厘米，宽40厘米，高30厘米．在空鱼缸里注入40升水，水深多少厘米？
<gadget id="calculator">50 * 40</gadget>
<output>2_000</output>

<gadget id="calculator">1_000 / 2_000</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">40 * (1/2)</gadget>
<output>20</output>

<result>20</result>