A cylindrical glass is filled with water, the water surface is 10 cm high, and the bottom area of the glass is 20 square centimeters. After putting a cube iron block with a side length of 4 cm into this glass, it is completely submerged. At this time, the water level is as high as for how much?
一个圆柱体玻璃杯中盛有水，水面高10厘米，玻璃杯的底面积是20平方厘米，在这个玻璃杯中放进棱长为4厘米的正方体铁块后，完全淹没，这时水面高为多少？
<gadget id="calculator">4 / 20</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">4 * 4 * (1/5)</gadget>
<output>16/5 = around 3.2</output>

<gadget id="calculator">(16/5) + 10</gadget>
<output>66/5 = around 13.2</output>

<result>66/5 = around 13.2</result>