For a ribbon, cut off the full length (1/3) for the first time, and cut off the full length (1/4) for the second time, how much of the full length is left.
一条彩带，第一次剪下全长的(1/3)，第二次剪下全长的(1/4)，还剩下全长的多少．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/3) - (1/4)</gadget>
<output>5/12 = around 0.416667</output>

<result>5/12 = around 0.416667</result>