A 2-meter-long iron wire is used up (1/2), how many meters are left?
一根2米长的铁丝，用去(1/2)，还剩多少米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

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

<result>1</result>