Three classes in the fifth grade participated in the voluntary tree planting activities. Among them, Class 51 planted 80 trees, the number of trees planted in Class 52 was that of Class 51 (7/8), and the number of trees planted in Class 53 was that of Class 52 ( 9/7), how many trees were planted by the three classes of the fifth grade?
五年级三个班级参加义务植树活动，其中五1班植了80棵，五2班植的棵数是五1班的(7/8)，五3班植的棵数是五2班的(9/7)，五年级三个班级共植树多少棵？
<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

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

<gadget id="calculator">9 / 7</gadget>
<output>9/7 = around 1.285714</output>

<gadget id="calculator">70 * (9/7)</gadget>
<output>90</output>

<gadget id="calculator">80 + 70 + 90</gadget>
<output>240</output>

<result>240</result>