12 meters long iron wire, use up (1/2), how many meters are left.
12米长的铁丝，用去(1/2)，还剩多少米米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">12 * (1/2)</gadget>
<output>6</output>

<gadget id="calculator">12 - 6</gadget>
<output>6</output>

<result>6</result>