A cuboid glass cylinder is 20 cm long, 15 cm wide, and 12 cm high when measured from the inside. There is water in the tank. If a cube iron block with a side length of 6 cm is placed in the water (completely submerged), how many centimeters will the water level rise?
一个长方体玻璃缸，从里面量长20厘米，宽15厘米，高12厘米，缸里装有水，把一个棱长6厘米的正方体铁块放入水中(完全浸没)，水面将上升多少厘米？
<gadget id="calculator">20 * 15</gadget>
<output>300</output>

<gadget id="calculator">6 / 300</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">6 * 6 * (1/50)</gadget>
<output>18/25 = around 0.72</output>

<result>18/25 = around 0.72</result>