A wire is 14 meters long, if (2/7) is used up, how many meters are left?
一根电线长14米，用去(2/7)，还剩下多少米．
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (2/7)</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">14 * (5/7)</gadget>
<output>10</output>

<result>10</result>