The students will plant 280 trees in total, 80 of which have been planted in the first 3 days, and the rest will be planted within 5 days. How many trees are planted per day on average?
同学们共要植树280棵，前3天已经植了80棵，剩下的要在5天内植完，平均每天要植树多少棵？
<gadget id="calculator">280 - 80</gadget>
<output>200</output>

<gadget id="calculator">200 / 5</gadget>
<output>40</output>

<result>40</result>