A piece of steel 3 meters long, cut off (1/2) of it first, and then cut off (1/2) meter, how much of the steel is left.
一根3米长的钢材，先截下它的(1/2)，再截下(1/2)米，还剩这根钢材的多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) / 3</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/2) - (1/6)</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>