I also remember reading that the French (maybe Denys will verify) also had a base-20 numbering system. The article provided as proof the fact that the words for 40, 60, 80... are two-twenties, three-twenties, four-twenties... Regards Paul H. Christidis ______________________________ Reply Separator _________________________________ Subject: Numbering conventions (was Re: Calendar redux) Author: [log in to unmask] at CCGATE Date: 07/28/97 04:52 AM Hi all ! I remember reading that the Maya (or some other Native American people ?) had a base-20 numbering scheme, using points and dashes to write numbers. In fact, it was more a 4 * 5 system. I do not really remember the specifics, just that it kind of was base-20 . Now, we have some "magic" numbers. 12 is one of them : the 12 tribes of Israel, 12 months of the year, the 12 cylinders on a Ferrari engine ... 7 is another one : 7 deadly sins, 7 days of the week ... Any other suggestions ? Christian