How to find items in the library

Marguerite Nel

Every book in the library is given an unique call number to serve as an address for locating the book on the shelf. The Academic Information Service uses the Dewey Decimal Classification System. This system groups material according to subject by using a combination of letters and numbers.

The following table illustrates the broad categories of the Dewey Decimal Classification System:

(Adapted from

Things that don't need man to exist - rain, rocks, plants, trees –are found in 500. In 600, we have things from 500, man made to work for him. For example, in 500, we have wolves but in 600 we have dogs. We grow the food in 500 but we cook it in 600. We have trees in 500 but we build houses from wood in 600.

Each of the above classes has ten divisions. These divisions are further divided, and then even further divided. Each division becomes more specific, the more numbers it gets. In this way, the Dewey classification system progresses from the general to the specific. The subcategories of the Dewey Decimal Classification System can be viewed at

To illustrate how the subdivision works, I’m going to use the example of the butterfly. You will agree with me that butterflies will be in the 500 field, because it is Natural Science.

Insects, including butterflies would be under 595. Now we have the first three numbers of the call number 595. The 595's are further divided by the use of decimals to specify what type of insect.

The following way will be followed to get to the specific call number for butterflies:

500--Natural Science

590--Zoological Sciences

595--Other invertebrates




This is the reason why some books have longer numbers than others. It all depends on how specific they are. Fifty percent of the books in the Veterinary Science Library start with 636. This is the Dewey number for Animal husbandry. 636.089 is the number for Veterinary science.

Books on horses are classed at 636.1. Surgery of the horse is 636.1 + 089 7 (0897 =veterinary surgery). So the number is 636.10897.

Compare this number with Human surgery which is 617 – short and sweet!

Books on animal diseases are placed at 636.089 6. So books on Diseases of the horse will be found at 636.10896.

Older books (received before 2000) are classed at a slightly different number for veterinary topics, however.
For instance, Surgery of the horse will be found at 636.0897 and Diseases of the horse at 636.0896.

It is therefore recommended that you use the library catalogue to search for books and not go directly to the shelves and browse, as certain books will be classed under 2 different Dewey numbers.

Dewey Decimal Classification System[Online]. [2006, February 23].
Dewey Decimal Game [Online].[2006, February 23].
How to understand the call numbers [Online].[2006, February 23].
Let's Do Dewey [Online]. [2006, February 23].