In order to green the city, a certain street needs to plant a batch of saplings. The survival rate of this batch of saplings is 80% to 90%. If 720 saplings are to survive, at least how many saplings should be planted.
为了绿化城市，某街道要栽种一批树苗，这批树苗的成活率是80%～90%，如果要保证成活720棵，至少要栽种多少棵．
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">720 / (9/10)</gadget>
<output>800</output>

<result>800</result>