In a glass tank with a length of 5 decimeters, a width of 4 decimeters, and a water depth of 2 decimeters, a cube of iron with a side length of 2 decimeters is placed. How many decimeters does the water surface rise to?
在一个长5分米，宽4分米，水深2分米的玻璃缸中，放入一块棱长2分米的正方体铁块，水面上升到多少分米．
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">2 / 20</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">2 * 2 * (1/10)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">2 + (2/5)</gadget>
<output>12/5 = around 2.4</output>

<result>12/5 = around 2.4</result>