The school planted 500 trees, and 390 survived. What is the survival rate?
学校植树500棵，有390棵成活，成活率为多少．
<gadget id="calculator">390 / 500</gadget>
<output>39/50 = around 0.78</output>

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

<gadget id="calculator">(39/50) * 1</gadget>
<output>39/50 = around 0.78</output>

<result>39/50 = around 0.78</result>