A greening team needs to plant 330 trees, 170 of which have already been planted, and the rest will be completed within 4 days. How many trees should be planted per day on average?
一个绿化队要植树330棵，已经植了170棵，剩下的要在4天内完成，平均每天要植树多少棵？
<gadget id="calculator">330 - 170</gadget>
<output>160</output>

<gadget id="calculator">160 / 4</gadget>
<output>40</output>

<result>40</result>