After 60% of the total length of a road has been repaired, there is still 800 meters left. What is the total length of this road in kilometers?
一条公路修了全长的60%后，还剩800米，这条公路全长多少千米．
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

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

<gadget id="calculator">800 / (2/5) / 1_000</gadget>
<output>2</output>

<result>2</result>