Book 3, Question 149
Why Do Libraries Use the Same Number Codes?
Shared numbers are like a map. If sharks are 597 in one town, they can be 597 in the next town too. So any library feels a little like home!
From the book
Page from A Million Whys Book 3
More fun facts
- Before the 1870s, many libraries grouped books loosely by subject or even by size.
- Melvil Dewey came up with his idea while working in his college library to pay his bills.
- His idea was to use decimal numbers to sort all knowledge in print.
- The Dewey Decimal System is built around the number ten, like the metric system.
- It has ten main areas, from General Works (000 to 099) to Geography and History (900 to 999).
- By 1900, a British librarian called it by far the most widely used library system.
Sources: Smithsonian Magazine
Questions kids ask
What do the numbers on library books mean?
In many libraries, the Dewey Decimal numbers show the book's subject, so books on the same topic sit together.