A rope is 6 meters long, the first time (1/3) of the full length is used, and the second time (1/3) of the full length is used, how much is left.
一根绳子长6米，第一次有去全长的(1/3)，第二次用去全长的(1/3)，还剩多少．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

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

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

<result>2</result>