There are 6 bookshelves in the school library, each shelf has 4 floors, and 25 books are placed on each floor. How many books are there in the library?
学校图书室有6个书架，每个书架有4层，每层放25本书，图书室一共有多少本书？
<gadget id="calculator">25 * 4 * 6</gadget>
<output>600</output>

<result>600</result>