First, the length of the rope is (5/7) meters, and if (2/7) meters are cut off, how many meters are left?
一要绳子长(5/7)米，剪去(2/7)米，还剩余多少米？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(5/7) - (2/7)</gadget>
<output>3/7 = around 0.428571</output>

<result>3/7 = around 0.428571</result>