highway has been repaired (1/5), and how much remains to be repaired.
一条公路，已修(1/5)，还剩多少没有修．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>