This year's Arbor Day, the school planted 72 trees, only 8 of which failed to survive, and later replanted 8, all of which survived. What is the survival rate of tree planting on Arbor Day this year?
今年植树节，学校种了72棵树，只有8棵未成活，后来又补种了8棵，全部成活．今年植树节植树的成活率是多少．
<gadget id="calculator">72 + 8</gadget>
<output>80</output>

<gadget id="calculator">72 / 80</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>