6 meters long wire, use up (1/2), how many meters are left.
6米长的电线，用去它的(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">6 * (1/2)</gadget>
<output>3</output>

<result>3</result>