A cube of iron with a side length of 20 cm is immersed in a rectangular parallelepiped glass tank with a length of 50 cm, a width of 40 cm and a height of 35 cm. How many cm does the water level in the tank rise?
把一块棱长20cm的正方体铁块浸入在一个长50cm，宽40cm，高35cm的长方体玻璃缸里，缸里的水面升高多少cm．
<gadget id="calculator">20 * 20 * 20</gadget>
<output>8_000</output>

<gadget id="calculator">50 * 40</gadget>
<output>2_000</output>

<gadget id="calculator">8_000 / 2_000</gadget>
<output>4</output>

<result>4</result>