How The Dewey Decimal Classification System
Works @ Your Library

Which Floor/Department of the Downtown Library? We have made a chart detailing the way we are organized. Hope this helps!

1 Dewey numbers divide humanity's knowledge, ideas, and artistic creations into ten major categories spanning a range from 000 to 999:

000 Generalities
100 Philosophy & psychology
200 Religion
300 Social sciences
400 Language
500 Natural sciences & math
600 Technology (Applied sciences)
700 The arts
800 Literature & rhetoric
900 Geography & history

2 Each major category divides into nine sub-categories spanning a range of 10 to 90. For example:

500 Natural science & mathematics 
510 Mathematics 
520 Astronomy & allied sciences 
530 Physics 
540 Chemistry & allied sciences 
550 Earth sciences 
560 Paleontology & paleozoology 
570 Life sciences 
580 Botanical sciences 
590 Zoological sciences

3 Each sub-category is further divided into nine specialized topics ranging from 1 to 9:

520 Astronomy
521 Celestial mechanics
522 Techniques, equipment, etc.
523 Specific celestial bodies
524 [Unassigned]
525 Earth (Astronomical geography)
526 Mathematical geography
527 Celestial navigation
528 Ephemerides
529 Chronology

4 By adding decimals, the specialized topics are broken down even further:

523.3 Moon
523.4 Planets
523.5 Meteors, solar wind, zodiacal light
523.6 Comets
523.7 Sun
523.71 Constants and imensions
523.72 Physics of
523.73 Motions
523.74 Photosphere
523.75 Chromosphere and corona
523.76 Solar interior
523.78 Eclipses

The Hundred Divisions

000 Generalities
010 Bibliography
020 Library & information sciences
030 General encyclopedic works
040 Special topics
050 General serials & their indexes
060 General organizations & museums
070 New media, journalism, publishing
080 General collections
090 Manuscripts & rare books

100 Philosophy & psychology
110 Metaphysics
120 Epistemology, causation, humankind
130 Paranormal phenomena
140 Specific philosophical schools
150 Psychology
160 Logic
170 Ethics (moral philosophy)
180 Ancient, medieval, oriental philosophy
190 Modern western philosophy

200 Religion
210 Natural theology
220 Bible
230 Christian theology
240 Christian moral & devotional theology
250 Christian orders & local churches
260 Christian social theology
270 Christian church history
280 Christian denominations & sects
290 Other & comparative religions

300 Social Science
310 General statistics
320 Political science
330 Economics
340 Law
350 Public administration
360 Social problems & services
370 Education
380 Commerce, communications, transport
390 Customs, etiquette, folklore

400 Language
410 Linguistics
420 English & Anglo-Saxon languages
430 Germanic languages (German)
440 Romance languages (French)
450 Italian, Romanian, Rhaeto-Romanic
460 Spanish & Portuguese languages
470 Italic languages (Latin)
480 Hellenic languages (Classical Greek)
490 Other languages

500 Natural science & mathematics
510 Mathematics
520 Astronomy & allied sciences
530 Physics
540 Chemistry & allied sciences
550 Earth sciences
560 Paleontology & Paleozoology
570 Life sciences
580 Botanical sciences
590 Zoological sciences

600 Technology (applied sciences)
610 Medical sciences (Medicine, Psychiatry)
620 Engineering
630 Agriculture
640 Home economics & family living
650 Management
660 Chemical engineering
670 Manufacturing
680 Manufacture for specific use
690 Buildings

700 The arts
710 Civic & landscape art
720 Architecture
730 Sculpture
740 Drawings & decorative arts
750 Paintings & painters
760 Graphic arts (Printmaking & prints)
770 Photography
780 Music
790 Recreational & performing arts

800 Literature & rhetoric
810 American literature in English
820 English literature
830 Literature of Germanic language
840 Literatures of Romance language
850 Italian, Romanian, Rhaeto-Romanic Literatures
860 Spanish & Portuguese literatures
870 Italic literatures (Latin)
880 Hellenic literatures (Classical Greek)
890 Literatures of other languages

900 Geography & history
910 Geography & travel
920 Biography, genealogy, insignia
930 History of the ancient world
940 General history of Europe
950 General history of Asia (Far East)
960 General history of Africa
970 General history of North America
980 General history of South America
990 General history of other areas

MORE QUESTIONS? If you have more questions about this classification system, go to http://www.oclc.org/dewey/resources/summaries/default.htm . If your question is about the Library of Cogress Classification system (an alternative system often used in academic libraries), go to http://loc.gov/catdir/cpso/lcco/

Which Floor/Department of the Downtown Library? We have made a chart detailing the way we are organized. Hope this helps!