A rope is 3 meters long, first cut off (1/2) of the full length, and then cut off (1/2) meter, how many meters are left.
一根绳子长3米，先截取全长的(1/2)，又截去(1/2)米，还剩多少米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 * (1/2)</gadget>
<output>3/2 = around 1.5</output>

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

<result>1</result>