# order (of a ring)

## Primary tabs

Defines:
finite ring
Synonym:
order, order of a ring
Type of Math Object:
Definition
Major Section:
Reference
Groups audience:

## Mathematics Subject Classification

### "order of a ring" with a vengeance

Due to the correction http://planetmath.org/?op=getobj&from=corrections&id=12149 and the posts that it generated, I have decided to add this definition. I also wanted to add this because I think that, to a person who is just learning abstract algebra, it might be confusing to click on "order" in a phrase like "order of a ring" and be redirected to an entry on order of a group. I made sure to include a disclaimer that the definition is not standard, and I have also cited sources in which this definition is used. (I was able to verify what CWoo said about the source that he provided. Thanks Chi!)

There are two things that I would *definitely* like to see edited:

1. If you know of any other sources that use "order of a ring", please add them! I do not intend to have an all inclusive list of such sources, but having some sources provided shows that the term is used, even if it is not standard.

2. I definitely do not want this entry to cause erroneous links! Please edit the linking policy as you see fit.

Warren

### Re: "order of a ring" with a vengeance

p.257, Computing and Combinatorics: 9th Annual International Conference, COCOON 2003, Big Sky, MT, USA

www-history.mcs.st-and.ac.uk/~jamesm/teaching/MT4517/MT4517-notes1.pdf
Remark 3.4.6
School of Mathematics and Statistics
MT4517 Rings & Fields
Lecture Notes 1

http://www.michmaa.org/meeting03/abstracts.html
John Skukalek, Grand Valley State University
Rings of Small Order

Rings of Small Order
Colin R. Fletcher
The Mathematical Gazette, Vol. 64, No. 427 (Mar., 1980), pp. 9-22
(Not even the abstract is available online without paying the
puiblisher, so I have no clue if this and the next reference are
relvant, but you might want to have a look)

http://portal.acm.org/citation.cfm?id=646656.700118
The Structure of Near-Rings of Small Order

http://home.wlu.edu/~dresdeng/smallrings/

http://www.algebra.uni-linz.ac.at/~noebsi/ringtable.html
Christof NÃ¶bauer
"Numbers of small rings"
"Transformation representations of minimal degree for small near-rings"

Benjamin Fine
Classification of Finite Rings of Order pÂ²
Mathematics Magazine, Vol. 66, No. 4

### Re: "order of a ring" with a vengeance

Thanks a lot for these links. I have added a couple of these which I was able to verify.

I found this source interesting as well as a little odd:

http://www.michmaa.org/meeting03/abstracts.html
John Skukalek, Grand Valley State University
Rings of Small Order

Part of the abstract reads:

A standard topic in a first class in group theory is the classification of all groups of small order. The classification of rings of small order is more difficult due to the more complicated structure. In this session we will present a complete classification scheme for all rings of order 5 or less.

Part of my motivation for researching cyclic rings was that ring classification is typically not studied in a first course in abstract algebra, whereas group classification and field classification is. The thing that weirds me out is that this person only considers classification schemes for rings up to order 5. If you are going to investigate rings of order 4 (which can be difficult, but I did manage to prove that there are 11 of them), why not do the easy cases of order 6 and order 7 as well?

Also, after looking at this source:

http://home.wlu.edu/~dresdeng/smallrings/

I contacted Dr. Dresden. He said that he will read Cyclic Rings and let me know what he thinks.