A batch of trees was planted, 30 survived, 4 died, and all 6 replanted later survived. What is the survival rate of this batch of trees?
栽一批树，活了30棵，死了4棵，后来补种的6棵全部成活，这批树的成活率是多少．
<gadget id="calculator">30 + 6</gadget>
<output>36</output>

<gadget id="calculator">30 + 4 + 6</gadget>
<output>40</output>

<gadget id="calculator">36 / 40</gadget>
<output>9/10 = around 0.9</output>

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

<gadget id="calculator">(9/10) * 1</gadget>
<output>9/10 = around 0.9</output>

<result>9/10 = around 0.9</result>