To build a road, (1/7) who builds this road every day can finish the repair more or less.
修一条路，每天修这条路的(1/7)，多少可以修完．
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 / (1/7)</gadget>
<output>7</output>

<result>7</result>