Mount Sackville Secondary School

Sisters of St.Joseph of Cluny, Chapelizod, Dublin 20

How the school library is arranged

The library consists of a collection of books, audio books, DVDs, videos, CDROMs, a Careers reference section, a collection of magazines and journals and we have 7 computers with internet access. Our collection of books is arranged into two main sections: Fiction and Non-Fiction.

(Please note some exceptions: English plays and poetry and literature in other languages are shelved in the non-fiction section according to the Dewey system.)

The Dewey Decimal Classification System

Every non-fiction book in the library has a number called the “shelfmark” that tells you where it is. This number is printed on a label on the spine of each book in the library. The books are shelved in sequence according to their numbers, and therefore their subjects.
The numbers are between 000 and 1000. They usually have a decimal point and can have many decimal places.
The hundreds represent broad topics, the tens represent subtopics, the ones represent sub subtopics, and the decimal places represent sub sub topics, and so on.
For example, a book on Irish Art would have the shelfmark 709.415. All of the books with numbers in the 700s are on the broad subject of Art and Recreation. Printmaking is at 760. The Impressionists are at 759.4.
You don’t have to learn the numbers. You just need to know the broad number for the subject you are interested in to browse the books. Ask the librarian where a book on a specific subject is, and she will tell you its Dewey shelfmark number.

Dewey subject areas

This is a useful online tour of how the Dewey Decimal System works: