primary school planted 500 trees last year, of which 15 did not survive. What is the survival rate?
一个小学去年植树500棵，其中未成活15棵．成活率是多少？
<gadget id="calculator">500 - 15</gadget>
<output>485</output>

<gadget id="calculator">485 / 500</gadget>
<output>97/100 = around 0.97</output>

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

<gadget id="calculator">(97/100) * 1</gadget>
<output>97/100 = around 0.97</output>

<result>97/100 = around 0.97</result>