In a cuboid container, pour an appropriate amount of water, and then put a cuboid iron block with a side length of 4 cm on the bottom surface. If all the iron blocks are put into the water, the water level in the container will rise by 10 cm. If a piece of iron sticks out of the water by 8 cm, the water level will drop by 4 cm. What is the height of the cuboid iron block in centimeters?
在一个长方体的容器里，倒入适量水，再放入一个底面边长是4厘米的长方体铁块，若铁块全部放入水中，则容器里的水面升高10厘米，若使浸没在水中的铁块露出水面8厘米，则水面下降4厘米．求长方体铁块的高是多少厘米？
<gadget id="calculator">8 / 4</gadget>
<output>2</output>

<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<result>20</result>