The third-grade students are going to plant 150 trees, 66 of which have already been planted, and the rest will be distributed to 3 groups. How many trees will each group plant on average?
三年级同学要植树150棵，已经植了66棵，剩下的分给3个小组，平均每个小组植树多少棵？
<gadget id="calculator">150 - 66</gadget>
<output>84</output>

<gadget id="calculator">84 / 3</gadget>
<output>28</output>

<result>28</result>