The document provides an overview of the Dewey Decimal Classification system and call numbers. It explains that Melvil Dewey created the system to organize the world's knowledge into 10 main categories. A call number contains information about a book's subject and author. For example, the call number 938 MAC means the book is about ancient Greece (history category 9, subject 3 for ancient, 8 for Greece) and written by author Fiona MacDonald. The document encourages readers to ask librarians for help understanding and using the Dewey Decimal system.

1. Dewey Decimal
Call Numbers
(or those numbers on the spine of every library book
that seem like they mean absolutely nothing actually
mean something.) 938
Mac
First Facts
on Ancient
Greeks
by
Fiona
MacDonaldOrganizing the world one book at a time

2. Who’s Dewey?
• That’s Melville Dewey
• Eccentric guy who wanted spelling
reform
– Liked to spell his name Melvil Dui.
– Dui <3 txt spk
• Big fan of Noah Webster, the creator of
modern American spelling, who liked
simplicity
• Made ten categories of knowledge for
everything we could ever possibly know
2
<3 the beard

3. An Outline of NonFiction Numbers
3
000 Generalities
100 Philosophy & psychology
200 Religion
300 Social sciences
400 Language
500 Natural sciences & mathematics
600 Technology (Applied sciences)
700 The arts
800 Literature & rhetoric

4. Call Numbers: They mean something to
somebody
A Typical Call Number at school
938
MAC
This number contains
information about the
book. 938 means that it
is in the History (9) and
specifically about
Ancient (3) Greece (8).
The first three letters of the
author’s last name.

5. Confused?
Think of a call number like an upside down
triangle
So, really broad (subject) to really exact (the book you’re
looking for). Make sense? See, we have reasons for
doing what we do.
And you thought librarians just did things to torture you.
Really, torturing you is only part of the reason.
9
3
8
Mac
General Subject (History)
Little more specific (Ancient)
Very Specific (Greece)
Exact Book (author)

6. Every Subject Known to Man
Librarians like to organize things. We call it call it
“classification” and we believe it makes things easier,
which may or may not be your opinion.
That’s too bad. We’re in charge.
So, there are many many many many subjects and
many many many many call numbers. Luckily, anyone
who uses Dewey Decimals can find pretty much the
same book in almost any library in the world.*
*Except universities in North America, which use Library of Congress Classification.
Fact: Giant, alien children attempting to take over world also
use the Dewey Decimals to organize their human slaves.

7. Dewey at the Public Library
8 Literature
2 English literatures
3 English fiction
.
9 1900
1 20th century
4 after 1945
R Author (Rowling)
797 Cutter Number (code for author’s last name)
H2 first letter of title
823.914 R797H2 =
Can you figure out what book this is?

8. Dewey Decimal Fiction
Technically, fiction books belong in
– 800 Literature
But this is annoying so usually all fiction
(for Bialik) is just in
– [FIC]
So you can find Harry Potter by JK
Rowling in:
[Fic] / Row
instead of 823.914 R797H2
You’re welcome

9. Be more like Indigo
9
Pros:
Easier for you
Cons:
• Librarians hate bias
• Harder to organize
• Change all the books to different
places on shelves and in computer

10. And knowledge is power!
If you take away only one thing,
take away this: Dewey
Decimals are your friends.
They can help if you know
how to use them.
And if you haven’t learned
anything or just don’t care,
there are a lot of librarians
waiting to help.
Dewey + You =

11. Ask for Help
Talk to your librarian. That’s what we’re here
for!