The fifth grade students planted a total of 300 trees, and 30 of them did not survive. What is the survival rate of these trees?
五年级同学共植树300棵，有30棵没成活，这批树的成活率是多少？
<gadget id="calculator">300 - 30</gadget>
<output>270</output>

<gadget id="calculator">270 / 300</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>