Master Zhang made 210 parts on the first day, 140 parts on the second day, and 250 parts on the third and fourth days. How many parts are made on average per day?
张师傅第一天做了210个零件，第二天做了140个零件，第三天与第四天共做了250个零件，平均每天做了多少个零件？
<gadget id="calculator">210 + 140 + 250</gadget>
<output>600</output>

<gadget id="calculator">600 / 4</gadget>
<output>150</output>

<result>150</result>