Jinfeng community has planted some trees this year, the ratio of the number of surviving trees to the number of dead trees is 4:1, the number of surviving trees accounts for ((())/(())) of this batch of trees, and the number of dead trees accounts for this batch of trees ((())/(())), what is the survival rate of this batch of trees.
金凤小区今年种了一些树，成活棵数与死去棵数的比是4：1，成活棵树占这批树的((())/(()))，死去棵数占这批树的((())/(()))，这批树的成活率是多少．
<gadget id="calculator">4 + 1</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>