Students in three classes of the sixth grade planted trees together, the first class planted 80 trees, the second class planted 7 more trees than the first class (9/8), and the third class planted 7 more trees than the second class (7/9) , How many trees are planted in the third shift?
六年级三个班学生共同植树，一班植树80棵，二班植树的棵数是一班的(9/8)，三班植树的棵数比二班的(7/9)还多7棵，三班植树多少棵？
<gadget id="calculator">9 / 8</gadget>
<output>9/8 = around 1.125</output>

<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">80 * (9/8) * (7/9)</gadget>
<output>70</output>

<gadget id="calculator">70 + 7</gadget>
<output>77</output>

<result>77</result>