There are 3 bookshelves in Xiao Ming's house, each with 4 floors, and each floor can hold 35 books. How many books can these bookshelves hold in total?
小明家里有3个书架，每个书架4层，每层可以放35本书，这些书架一共可以放多少本书？
<gadget id="calculator">35 * 4 * 3</gadget>
<output>420</output>

<result>420</result>