For a 18-meter-long rope, use the full length (1/3) for the first time, and use the remaining (1/2) for the second time. How much rice is left?
一根18米长的绳子，第一次用去全长的(1/3)，第二次用去余下的(1/2)．还剩多少米？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(2/3) * (1/2)</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">18 * (1/3)</gadget>
<output>6</output>

<result>6</result>