5.5 meters of iron wire, use up (3/5) of the full length, and leave the full length ((())/(())), how many meters are left.
5.5米的铁丝，用去全长的(3/5)，还剩全长的((())/(()))，还剩多少米．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">5.5 * (2/5)</gadget>
<output>2.2</output>

<result>2.2</result>