Roman Numeral

Date: 7/10/96 at 9:36:19
From: Anonymous
Subject: Roman Numeral "D"

What does the Roman numeral D stand for? I know the value is 500. I 
looked in our textbooks and the dictionary. I don't know where else 
to look. Please help. 

Thanks! 
P.S. I love this site!

Date: 7/11/96 at 10:23:26
From: Doctor Mike
Subject: Re: Roman Numeral "D"
  
Hello, 

I went to our web site (see below) and selected the Search Dr. Math 
Archives link to search for information on Roman Numerals. One thing I 
found was an annotated lesson plan on Roman Numerals by Bess Kuzma of 
St. Pius X School in Aurora, Colorado. 



Here is a selection from her background material that answers your 
question.

   Roman numerals were developed around 500 B.C. at least partially 
   from primitive Greek alphabet symbols which were not incorporated 
   into Latin.  ..........

   Until fairly recently a commonly used Roman numeral for 1,000 was 
   "CI backwards C", derived from the Greek "phi", or "I" superimposed 
   on "O". Half of this symbol, "I backwards C", led to "D" for 500, 
   half of 1,000.
  
I hope this helps. 

-Doctor Mike,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/