Li Zhuang built a water canal, which is 220 meters long, which is 20 meters shorter than the full length (4/5). How long is this canal in meters?
李庄修一条水渠，现在已经修完220米，比全长的(4/5)少20米．这条水渠全长多少米？
<gadget id="calculator">220 - 20</gadget>
<output>200</output>

<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>