This is a primary school math problem. There are two bookshelves on the eighth floor, with 480 books on each floor, with an average of 80 books.

Data expansion:

Bookshelf is an instrument specially used by people to put books. Because of the different forms and structures of bookshelves, there are different names such as bookcase, bookcase and book partition. Bookshelves are common appliances in our lives.

Bookshelves in libraries can be divided into metal bookshelves and wooden bookshelves according to materials, and metal bookshelves can be subdivided into single-column bookshelves, multi-column bookshelves, stacked bookshelves, dense shelves and sliding bookshelves.

The materials of wooden bookshelves are solid wood, plywood, wood core board, particleboard and so on. , after processing and combination, coated with paint or affixed with surface decoration materials, rich in soft texture. The common form of library is vertical inclined L-shaped bookshelf, which is convenient for readers to consult books and has different specifications.

The so-called single-column bookcase means that both sides bear the weight of books on each partition horizontally with single-column metal plates. Each bookshelf is 90cm long and can be used alone or placed continuously. Generally speaking, the height of the bookshelf is more than 200cm, and the top will be connected with tie rods to ensure safety.

In order to make full use of the limited space in the stacks to store a large number of books, it is a good method to provide stacked bookshelves with books by applying the durable characteristics of steel materials.

However, different countries have their own bookshelf specifications. For example, laminated bookshelves in the United States have a clear height of 2280mm on each floor, and each floor is divided into 5-7 sections. In European countries such as Britain, the clear height of each floor is 2250mm, the width of one partition is 200mm, and the width of columns is 50 mm..