The school library bought 2 bookshelves, each with 5 floors, and 30 books on each floor, how many books can be placed in total?
学校图书馆买来2个书架，每个书架有5层，每层放30本书，一共可以放多少本书？
<gadget id="calculator">5 * 2 * 30</gadget>
<output>300</output>

<result>300</result>