piece of rope 10 meters long, minus half of it, how many meters are left.
一段10米长的绳子，减去它的一半，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">10 * (1/2)</gadget>
<output>5</output>

<result>5</result>