[NBLUG/talk] Invention of the Unary Number System

[Eric Eisenhart]

On Mon, May 19, 2003 at 02:23:54PM -0700, Steve Zimmerman wrote:
> 0	.... "1"
> 00	.... "2"
> 000	.... "3"
> 0000 	.... "4"
> 00000	.... "5"
> etc.
> : -)

There's a more commonly seen unary numbering system, but the discovery of 0
and its many uses eventually made it largely obsolete.  It's based on
counting on the hands.

It goes like this:
I     .... "1"
II    .... "2"
III   .... "3"
IIII  .... "4"
IIIII .... "5"
 But that last one is starting to get kinda long to write, so, since we're
 counting on our fingers and one full hand has a certain shape between thumb
 and index finger when all fingers are out:
V     .... "5"
 And using a little addition to keep things short: 
VI   .... "6"
VII  .... "7"
VIII .... "8"
VIIII.... "9"
VV   .... "10"
 Then you have the shape of two crossed index fingers (or crossed arms?)
 signifying a complete set of 2 hands, so instead of VV, you have:
X    .... "10"
XV   .... "15"

This all makes more sense if you're counting military units, where each type
of commander is in control of a certain sized unit.  The key operating unit
was typically 100 soldiers (XXXXXXXXXX or MM), aka a "century" of
"centurions" counted as "C"=100".

Later, because these got too long, they came up with a system that included
subtraction along with the addition, giving you:
IV = 4
IX = 9
XIV = 14
IC  = 99
etc.

But it's all just ways to abbreviate lots of fingers:
IIIII IIIII 

(Seriously, the Romans found 0 so scary that they outlawed it)
-- 
Eric Eisenhart
NBLUG Co-Founder & Vice-President Pro Tempore
The North Bay Linux Users Group
http://nblug.org/
eric at nblug.org, IRC: Freiheit at freenode, AIM: falschfreiheit, ICQ: 48217244