The ratio of the saplings that did not survive to the saplings that have survived is 1:4, so what is the survival rate of the saplings?
没有成活的树苗和已经成活的树苗的比是1：4，那么树苗的成活率是多少．
<gadget id="calculator">1 + 4</gadget>
<output>5</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

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

<gadget id="calculator">(4/5) * 1</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>