This year's Arbor Day, the students planted 80 trees, 9 of which did not survive. Later, we replanted 20 trees, and 2 of them failed. What is the survival rate of the trees planted by the students?
今年植树节，同学们种植了80棵树，有9棵没有成活，后来大家补种20棵，又有2棵没成活，同学们植树的成活率是多少．
<gadget id="calculator">80 - 9</gadget>
<output>71</output>

<gadget id="calculator">20 - 2</gadget>
<output>18</output>

<gadget id="calculator">71 + 18</gadget>
<output>89</output>

<gadget id="calculator">80 + 20</gadget>
<output>100</output>

<gadget id="calculator">89 / 100</gadget>
<output>89/100 = around 0.89</output>

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

<gadget id="calculator">(89/100) * 1</gadget>
<output>89/100 = around 0.89</output>

<result>89/100 = around 0.89</result>