The end of every shelf shows what number books you will find there
How do I find a book on the shelves?
Libraries have a lot of books, and we need to be able to find them! And so, non-fiction fact books are given a number and sometimes letters that we stick to the spine. The numbers are for what the books are about, the topic. You don't need to know the numbers, it's just to explain how they work. Signs on the bookshelves and library staff can help you find what you need.