To commemorate the 90th anniversary of the founding of the Communist Party of China, the Young Pioneers planted commemorative trees, planted 100 pine trees, and survived 90 classes. What is the survival rate of the pine trees?
为了纪念建党90周年，少先队种植纪念树，栽下100棵松树，成活了90课，松树的成活率是多少？
<gadget id="calculator">90 / 100</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>