The Dewey Decimal Classification System

by Jean Halsey


 The purpose of this lesson is to teach students about the fundamentals of the Dewey Decimal System to enable them to locate books in the library.   Many students are overwhelmed when entering the library because of the vast amounts of books on the shelves.  Learning the Dewey Decimal Classification System will guide the students to the books of their choice!




The Dewey Decimal Classification System is the most widely used method for classifying books in the library. This system is a general knowledge organization tool that is continuously revised to keep pace with knowledge.  It is named after Melvil Dewey, an American Librarian who developed it in 1876. This system is a numerical scheme for the arrangement of subjects of nonfiction books, and it classifies books by dividing them into 10 main subject groups that are called categories. Each category is represented by figures beginning with 000 and going on to 999. In other words, it is a system of numbers used to mark and arrange mostly non-fiction books.

Each number stands for a special topic. Every book is given a number and is put on the shelf in number order. Books with the same number are put in alphabetical order by the author’s last name.  There are three summaries of the DDC.  The first summary contains the ten main classes. The first digit in each three-digit number represents the main class. For example, 500 represents natural sciences and mathematics.  The second summary contains the hundred divisions. The second digit in each three-digit number indicates the division. For example, 500 is used for general works on the sciences, 510 for mathematics, 520 for astronomy, 530 for physics. The third summary contains the thousand sections. The third digit in each three-digit number indicates the section. Thus, 530 is used for general works on physics, 531 for classical mechanics, 532 for fluid mechanics, 533 for gas mechanic.  A decimal point follows the third digit in a class number, after which division by ten continues to the specific degree of classification needed. A subject may appear in more than one discipline. For example, "clothing" has aspects that fall under several disciplines. The psychological influence of clothing belongs in 155.95 as part of the discipline of psychology; customs associated with clothing belong in 391 as part of the discipline of customs; and clothing in the sense of fashion design belongs in 746.92 as part of the discipline of the arts. 

The Dewey Decimal Classification System is used in most Public School libraries. It is essential for students to understand why books are numbered and how to find the numbers on the shelves, so they can use the library effectively and in a friendly manner. Dewey is also used for other purposes, e.g., as a browsing mechanism for resources on the Web. One of Dewey's great strengths is that the system is developed and maintained in a national bibliographic agency, the Library of Congress.


The students will be able to:


Computer, pen, pencil, paper and handouts identifying the categories of the Dewey Decimal System.


Are You Ready To “Dew” It?




000-099 General References or Works (encyclopedias, biographies, periodicals and journalism)
100-199 Philosophy, psychology and logic
200-299 Religion (men’s faith)
300-399 Social Sciences (how people live and work in society; law, government and institutions)
400-499 Language (English, grammar and dictionaries)
500-599 Natural Science (Mathematics, astronomy, physics, chemistry, geology, paleontology, biology, zoology, and botany)
600-699 Technology and Applied Science (medicine, engineering, agriculture, home economics, radio, TV, and aviation)
700-799 Fine Arts and Recreation (architecture, sculpture, painting, music, photography and recreation)
800-899 Literature (plays, poems, essays, literature in foreign languages)
900-999 History and Biography (history, biography, geography and other related disciplines)


Dewey Decimal Quiz

  1. The book “Fishing with Dad” has the Dewey number 799.  What does each number represent?

  2. Using the Dewey numbers, arrange the following numbers in order:  796.1, 796.9, 796.4, 796.01, and 796.12.

  3. Name the continent represented by the call number 916.

  4. Books about trees have this call number ___________.

  5. What class division would you check to locate a book on occupations?

Answers to Quiz:

  1. 7 represents “Fine Arts”
    the second 9 represents “recreation”
    the third 9 represents “hunting fishing and shooting”

  2. 796.01

  3. Africa

  4. 582

  5. 300

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