Qingshui Lake planted 400 trees in spring, 10 of which did not survive. Find the survival rate.
清水湖春季植树400棵，未成活的有10棵．求成活率．
<gadget id="calculator">400 - 10</gadget>
<output>390</output>

<gadget id="calculator">390 / 400</gadget>
<output>39/40 = around 0.975</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(39/40) * 1</gadget>
<output>39/40 = around 0.975</output>

<result>39/40 = around 0.975</result>