A certain school has 260 students in the first grade, 300 students in the second grade, and 280 students in the third grade. How many students are there on average in each grade?
某校一年级有260人，二年级有300人，三年级有280人，平均每个年级有多少人？
<gadget id="calculator">260 + 300 + 280</gadget>
<output>840</output>

<gadget id="calculator">840 / 3</gadget>
<output>280</output>

<result>280</result>