The Dewey Decimal Classification system was first created by a chap called Melvil Dewey, all the way back in 1876. That’s him, just there. →
Essentially Melvil’s system organises every single possible non-fiction book by a set of numbers, meaning that no matter the subject, it can be found easily in any library, anywhere. (Or, at the current count, 200,000 libraries in at least 135 countries.)
The system is pretty simple when you get your head around it.
There are three digits before a decimal point and between zero and about eight or so after the point, although we don’t go above three in the ILC. 000.0 – 999.99999999
The first number tells you what the general subject is (as above in the picture), and then each further one tells you more about the subject, and gets more specific.
For example, if you were looking for a book on generic “science” you’d look under 500
However, if you wanted Physics, you’d look for 530.
538 would get you magnetism.
538.3 is electromagnetism.
And, 538.36 is nuclear magnetic resonance
And if you wanted to get really specific, with electron paramagnetic resonance you could go directly to 538.364, and find just the book you needed.
The ILC has some handy guides organised alphabetically by subject to help you find the right book. You can also search the catalogue by double clicking on the clever icon on the desktop when you log on at school. You can also use this map of the ILC to direct you by subject to the area you need.