The school planted 500 trees, but 10 did not survive. What is the survival rate?
学校植树500棵，有10棵没有成活，成活率为多少
<gadget id="calculator">500 - 10</gadget>
<output>490</output>

<gadget id="calculator">490 / 500</gadget>
<output>49/50 = around 0.98</output>

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

<gadget id="calculator">(49/50) * 1</gadget>
<output>49/50 = around 0.98</output>

<result>49/50 = around 0.98</result>