A batch of saplings were planted, 180 of them survived, and the survival rate was 90%. How many saplings are there in this batch?
种一批树苗，活了180棵，成活率为90%，这批树苗有多少棵．
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">180 / (9/10)</gadget>
<output>200</output>

<result>200</result>