My name is Melvil Dewey. I invented the Dewey Decimal Classification System in 1876.

Until then, every library had a different way of organizing nonfiction books.

Public libraries and school libraries still use my system for organizing their books.

It’s very easy to use. The numbers tell you what the books are about.

Ten Main Classes of the Dewey Decimal Classification System

000     Generalities
            001.9 Controversial Knowledge (weird stuff like Big Foot, UFOs & Loch Ness Monster)
            004 Computers and the Internet
            030 History facts
            031 Encyclopedias and books of facts like the Guinness Book of World Records
            060.42 How to run a meeting

100      Philosophy, Psychology & Unexplained Phenomena

200      Religion

300      Social Sciences

400      Languages

500     Science & Math

600      Technology

700      The Arts & Sports

800     Literature

900     Geography & History
            921 Biographies