All YPL locations will be closed Sunday, Feb. 12 & Monday, Feb. 13 in observance of Lincoln’s Birthday and Sunday, Feb. 19 & Monday, Feb. 20 in observance of Washington’s Birthday.

Dewey Decimal System Day

When you walk into the library, you probably have a pretty good idea of the type of book you’re looking for. Maybe you’re doing research on World War II for a history paper, or you’re looking for a cookbook because you want to try eating more vegetarian food, or maybe you want to learn some mindfulness tips from a self-help book. No matter what you want to read, the library has it, and you don’t have to spend much time looking for it thanks to the Dewey Decimal System. 

December 10th is Dewey Decimal System Day, a celebration of the organizational system that has kept libraries organized since it was first proposed by Melvil Dewey in 1876. All books within a library’s collection – particularly nonfiction books – are sorted by the Dewey Decimal System.

The numbers you see on the label on a book’s spine aren’t random. There are 10 main groups of classification within the Dewey Decimal System:

  • General Works: 000–099,
  • Philosophy and Psychology: 100–199
  • Religion: 200–299
  • Social Sciences: 300–399
  • Language: 400–499
  • Natural Sciences and Mathematics: 500–599
  • Technology: 600–699
  • The Arts: 700–799
  • Literature and Rhetoric: 800–899
  • History, Biography and Geography: 900–999

These groups are broken down further into more specific subjects and, with a little help from your local librarian, are easily found. Could you imagine wandering around the library for hours, looking for that perfect read without any sort of system to make it easier? The modern library is possible because of the Dewey Decimal System.

Check out some of these great reads about the Dewey Decimal System and about the great role that libraries play in your community and in the history of our world. Happy Reading!


Alison Robles is a part-time clerk at the Crestwood Library. She is an avid reader with a passion for fantasy, history and science fiction. A Yonkers native, she graduated from Iona University in 2020 with a dual-degree in Marketing and Public Relations.