10m long rope, cut (2/7) for the first time, and (3/7) for the second time, what fraction of the rope is left now?
一根10m长的绳子，第一次剪去(2/7)，第二次剪去(3/7)，现在还剩下这根绳子的几分之几？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (2/7) - (3/7)</gadget>
<output>2/7 = around 0.285714</output>

<result>2/7 = around 0.285714</result>