Understanding Call Numbers

What are call numbers for?

Each book in the library has a unique call number. A call number is like an address: it tells us where the book is located in the library.  Call numbers appear 

Note that the same call number can be written from
top-to-bottom, or left-to-right. 

Reading Call Numbers

Putting Call Numbers in Shelf Order

To understand how call numbers are put in order in Dewey Decimal Classification, again look at each section of the call number.

What does the call number mean?

Remember that Dewey Decimal Classification arranges materials by subjects. The first sections of the call number represent the subject of the book. The letter-and-number section of the call number often represents the author's last name. And, as you probably recall, the last section of a call number is often the date of publication.  For example:

Why is this important to know?
Because books are classified by subject, you can often find several helpful books on the same shelf, or nearby. For example, within the same call number 595.789, there are other books about butterflies or similar topics.

Since Dewey Decimal Classification arranges materials by subjects, knowing the number(s) for your subject area gives you a place to start browsing the shelves.