The students planted 120 trees, and 20 of them did not survive. What percentage of the trees that did not survive were the trees that survived?
同学们栽树120棵，没有成活的有20棵，没有成活的棵树是成活棵树的几分之几？
<gadget id="calculator">120 - 20</gadget>
<output>100</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>