An iron block with a volume of 80 cubic centimeters is immersed in a cuboid container with a bottom area of 20 square centimeters, and the height of the water surface is 10 cm. If the iron block is taken out, how high is the water surface?
把一个体积为80立方厘米的铁块浸在底面积为20平方厘米的长方体容器中，水面高度为10厘米，如果把铁块捞出后，水面高多少？
<gadget id="calculator">80 / 20</gadget>
<output>4</output>

<gadget id="calculator">10 - 4</gadget>
<output>6</output>

<result>6</result>