Classes 31, 2, and 3 actively recycle 420 waste batteries. There are 5 groups in each class. How many waste batteries do each group recycle on average?
三1、三2、三3班的同学积极回收废电池共420节，每班有5个小组，平均每个小组回收多少节废电池？
<gadget id="calculator">420 / 3 / 5</gadget>
<output>28</output>

<result>28</result>