A canal has been built for 200 meters, and it is just finished (4/5). How long is the canal in meters?
修一条水渠，已经修了200米，正好修了(4/5)，水渠全长多少米？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">200 / (4/5)</gadget>
<output>250</output>

<result>250</result>