Pour 5 liters of water into a glass jar with a length of 0.5 meters and a width of 0.4 meters.
把5升水倒入长0.5米，宽0.4米的玻璃缸里水深多少分米．
<gadget id="calculator">0.5 * 10 * 0.4 * 10</gadget>
<output>20</output>

<gadget id="calculator">10 / 20</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">0.5 * (1/2)</gadget>
<output>0.25</output>

<result>0.25</result>