A piece of steel 3 meters long, use up (1/2) of it first, and then cut off (1/2) meter, how many meters are left at this time
一根3米长的钢材，先用去它的(1/2)，再截去(1/2)米，这时还剩多少米
<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">3 * (1/2)</gadget>
<output>3/2 = around 1.5</output>

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

<result>1</result>