Following these rules, the formation of the numbers is intuitive: the number would be split into hundreds, tens and units and the letters combined to give the graphical representation. This was a derived version of the addition numerical system that was used in the ancient times. An additional problem was the fact that the system proved difficult to use initially for numbers that were larger than 999. What the Greeks did was add an extra stroke before the letter to symbolize that the respective number would be multiplied by 1000. This meant that you would now be able to include any kind of larger numbers with that stroke.

With the fractions, there were different representations that the Greeks used. One of them involved marking the denominator with a double accent and sometimes writing it down twice. However, there was also the representation we are mostly used to nowadays by which the nominator and denominator are simply placed one over the other, but the fraction would be missing.

As mentioned in the introduction, the Greek numerals...

Classical Greek numerals. On the Internet at http://www.sizes.com/numbers/greek_numeration.htm.Lastretrieved on February 28, 2009
2. Bunt, Lucas; Jones, Phillip. The Historical Roots of Elementary Mathematics. Dover Publications. 1988.

3. Hardegree, Gary. Numeration Systems. 2001. On the Internet at http://www-unix.oit.umass.edu/~gmhwww/382/pdf/05-numeration.pdf.Lastretrieved on February 28, 2009

Classical Greek numerals. On the Internet at http://www.sizes.com/numbers/greek_numeration.htm.Lastretrieved on February 28, 2009

Bunt, Lucas; Jones, Phillip. The Historical Roots of Elementary Mathematics. Dover Publications. 1988.

Hardegree, Gary. Numeration Systems. 2001. On the Internet at http://www-unix.oit.umass.edu/~gmhwww/382/pdf/05-numeration.pdf.Lastretrieved on February 28, 2009

Bunt, Lucas; Jones, Phillip. The Historical Roots of Elementary Mathematics. Dover Publications. 1988.