The school bought 10 boxes of chalk, and after using up 250 boxes, there are still 550 boxes left. How many boxes are there on average?
学校买来10箱粉笔，用去250盒后，还剩下550盒，平均每箱多少盒？
<gadget id="calculator">250 + 550</gadget>
<output>800</output>

<gadget id="calculator">800 / 10</gadget>
<output>80</output>

<result>80</result>