The school library bought 350 story books and 280 popular science books. Put these new books in 3 reading rooms, how many books are placed in each reading room on average?
学校图书馆买来350本故事书和280本科普书．把这些新书放在3个阅览室，平均每个阅览室放多少本？
<gadget id="calculator">350 + 280</gadget>
<output>630</output>

<gadget id="calculator">630 / 3</gadget>
<output>210</output>

<result>210</result>