Build a road, and there are 800 meters left after repairing (3/5). How long is this road in meters?
修一条路，修了(3/5)后还剩800米，这条路长多少米．
<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>

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

<result>2_000</result>