The school library bought 520 books and placed them on 2 bookshelves, each with 4 floors, how many books are placed on each floor on average?
学校图书室买来了520本书，放在2个书架上，每个书架有4层，平均每层放多少本书？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">520 / 8</gadget>
<output>65</output>

<result>65</result>