The school bought 4 bookshelves, each with 5 layers, and each layer can hold 36 books. How many books can these bookshelves hold in total?
学校买来4个书架，每个书架有5层，每层可以放36本书，这些书架一共可以放多少本书？
<gadget id="calculator">36 * 5 * 4</gadget>
<output>720</output>

<result>720</result>