There are 20 bookshelves in the school library, each shelf has 5 floors, and an average of 80 books can be placed on each floor. How many books can be placed in total?
学校图书室有20个书架，每个书架有5层，平均每层放80本书，一共可以放多少本书？
<gadget id="calculator">80 * 5 * 20</gadget>
<output>8_000</output>

<result>8_000</result>