The library newly purchased 216 books and plans to put them on 2 identical bookshelves. Each bookshelf has 4 floors. How many books should be placed on each floor on average?
图书室新购216本图书，打算放在2个同样的书架上，每个书架有4层，平均每层要放几本图书？
<gadget id="calculator">216 / 2 / 4</gadget>
<output>27</output>

<result>27</result>