The Dewey Decimal System is a type of organization used in libraries for the classification and arrangement of books. The system was created by Melvil Dewey, a librarian, in 1876, and it quickly began to be adopted by libraries across the country. The Dewey Decimal System classifies each book into one of ten subject areas, and each subject is further divided into a subdivision. Throughout all libraries that use the system, each of the ten categories are the same and are numbered, starting in the hundreds. Books are further classified into more sub-categories, eventually ending in decimals to define the exact category. By following this method, a person can find a book of any subject by determining what its number should be. The Dewey Decimal System is employed at over 200,000 libraries in the world, and all books within those libraries are classified in this way.

000 Generalities
010 Bibliography
020 Library Science
030 Encyclopedias
040 Unassigned
050 Magazines
060 Organizations, museums
070 Journalism
080 General collections
090 Manuscripts, rare books

100 Philosophy
110 Metaphysics
120 Epistemology
130 Paranormal phenomena
140 Specific philosophies
150 Psychology
160 Logic
170 Ethics
180 Ancient philosophy
190 Modern philosophy

200 Religion
210 Natural theology
220 Bible
230 Christian theology
240 Christian moral theology
250 Christian orders
260 Christian social theology
270 Christian church history
280 Christian denominations
290 Other religions

300 Social science
310 General statistics
320 Political science
330 Economics
340 Law
350 Public administration
360 Social services
370 Education
380 Commerce, transport
390 Customs, folklore

400 Language
410 Linguistics
420 English
430 German
440 French
450 Italian, Romanian
460 Spanish, Portuguese
470 Latin
480 Classical Greek
490 Other languages

500 Science
510 Mathematics
520 Astronomy
530 Physics
540 Chemistry
550 Earth sciences
560 Paleontology
570 Life sciences
580 Botany
590 Zoology

600 Technology
610 Medicine
620 Engineering
630 Agriculture
640 Home economics
650 Management
660 Chemical engineering
670 Manufacturing
680 Specific industries
690 Buildings

700 Arts & entertainment
710 Civic & landscape art
720 Architecture
730 Plastic arts, sculpture
740 Drawing, decorative arts
750 Painting
760 Graphic arts, printmaking
770 Photography
780 Music
790 Recreation, performing arts

800 Literature
810 American
820 English
830 German
840 French
850 Italian, Romanian
860 Spanish, Portuguese
870 Latin
880 Classical Greek
890 Other literature

900 Geography & history
910 Geography & travel
920 Biography, genealogy
930 History of ancient world
940 History of Europe
950 History of Asia
960 History of Africa
970 History of North America
980 History of South America
990 History of other areas

“Do We” Really Know Dewey?: An explanation of the history of the Dewey Decimal System, which also includes quizzes and games for classification practice.

Let’s Do Dewey: The history of Melvil Dewey, founder of the Dewey Decimal System

Exploring the Dewey Decimal System: A brief account of the history of the system, as well as an example classification.

How to Use the Dewey Decimal System: An interpretation of each of the divisions for classification.

Dewey Decimal Classification System: A look at each of the divisions that are used for classification within the system.

Awesome Library: An explanation of the Dewey Decimal System with practice exercises and activities.

Dewey Decimal Numbers for Kids: A breakdown of the different classification categories.

Using the Dewey Decimal System: The explanation of categories to locate resources within the library.