What is Dewey Anyway?
Melvil Dewey, one of the greatest librarians of all time, invented this system in 1876. He wanted to create a way for librarians and users to be able to find books quickly and easily on the shelves. 130 years later, we still use the Dewey Decimal System as the way for librarians to organize books. It may look confusing, but if you understand the 10 different categories, it will become very simple. Look at the spine of a book, the numbers count from 000-999. Each number means a different subject.
000s--The zeroes begin a subject called generalities. These are encyclopedias, supernatural (UFOs and ghosts), computers, Guinness Record books, and almanacs.
100s--Philosophy and psychology
200s--Religion
300s-- Social sciences (this includes education and crime)
400s-- Language (dictionaries and foreign language)
500s-- Natural science and mathematics
600s--Technology (but not computers, Dewey was invented way before that!? Cooking and health are found here.)
700s-- Art and sports
800s-- Literature (poetry, writing, and plays)
900s-- History (biography is 920)
Subcategories
Now that you understand how each hundred represents a subject, you can learn how the subcategories work. Each major category subdivides into 9 smaller categories that all relate to the head category.
For example:
500 Natural science and mathematics
510 Mathematics
520 Astronomy
530 Physics
540 Chemistry
550 Earth sciences
560 Paleontology
570 Life sciences
580 Botanical sciences
590 Zoological sciences
So, if you are looking for a book about polar bears, you now know that belongs in the 500s for science. If you know those subcategories, you will know that animals will be found in the 590s because that number is designated for zoological sciences. Would you believe the subcategories divide into 9 smaller specialized categories? It's true. If you are looking for polar bears, they will be found under this specialized number for mammals, which happens to be 9. This creates a Dewey decimal number for mammals as 599. The decimals found at the end of some numbers help the specialized numbers become more specific. By adding a decimal point, it will represent polar bears. Polar bears are represented as a .7 Therefore, a book about polar bears will be found under 599.7
