Put a 10 cm square iron block into a glass tank with a length of 50 cm, a width of 40 cm and a height of 30 cm. The depth of the water in the tank was originally 20 cm. How many centimeters does the water level rise now?
把一个棱长10厘米的正方体铁块放入一个长50厘米、宽40厘米、高30厘米的玻璃缸中，原来缸中水深20厘米，现在水面升高几厘米？
<gadget id="calculator">50 * 40</gadget>
<output>2_000</output>

<gadget id="calculator">10 / 2_000</gadget>
<output>1/200 = around 0.005</output>

<gadget id="calculator">10 * 10 * (1/200)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>