A road with a length of 1 kilometer has been paved (3/5) kilometers, how many kilometers are left unpaved?
一条长1千米的路，已铺好了(3/5)千米，还剩下多少千米没有铺好？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>