If (1/2) of a rope is used up and then the remaining (1/3) is used up, what is the remaining length of the rope?
一根绳用去(1/2)后又用去余下的(1/3)，这时还剩全长的多少．
<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">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

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