A workshop originally planned to process 420 parts in 7 days, but actually completed it 2 days ahead of schedule, and actually processed how many parts per day on average.
某车间原计划7天加工420个零件，实际提前2天完成，实际平均每天加工多少个零件．
<gadget id="calculator">7 - 2</gadget>
<output>5</output>

<gadget id="calculator">420 / 5</gadget>
<output>84</output>

<result>84</result>