There were 40 students in Class 1 of June 1 who were participating in the tree planting activity. They planted 20 saplings, but 2 of them did not survive. What is the survival rate of these saplings?
六1班有40名同学在参加植树活动，种下20棵树苗，有2棵没有成活．这批树苗的成活率是多少．
<gadget id="calculator">20 - 2</gadget>
<output>18</output>

<gadget id="calculator">18 / 20</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>