Why base 10 ?
The most common base in history
Conflicting forces TheoreticianPragmatist
Tigris-Euphrates River Valley
Mesolithic and Neolithic tokens from the Middle East As early as 9 th millennium
Pictograms
Development of Pictograms into Cuneiform
Archaic Sumerian numbers
Ancient Sumerian Writing
Bulla, Calculus, and Seals
Bulla: binding contracts in an illiterate society
the enigma of sexagesimal base
the enigma of the sexagesimal system ► origin unknown but…vestiges remain today ► numerous hypotheses smallest number with greatest number of dividers mixture of pre-existent base 10 and the new base 60 of emigrants mystical reasons- cult of the celestial god
Long division Sumerian-style ►E►E►E►Example from 2650 B.C. in Šuruppak ►1►1►1►1,152,000 sìla of barley ►E►E►E►Each person must get 7 sìla ►H►H►H►How many people will get barley?
Šà rgal-i á Šà r-u-min 1,152,000 Literally means Literally means 216,000 x ,000 x 2 or or 5 x x (10 x 60 2 )
how the Sumerians did their sums
Calculation with pellets, cones, and spheres
After the eclipse of Sumer Babylonia ► Everyday Babylonia strictly decimal ► Stopped using calculi ► Most probably had a counting device ► Developed the rule of position ► Developed the idea of zero
Babylonian positional numbering