WRITNG SEXAGESIMAL NUMBERS - MODERN NOTATION

To write numbers in the Babylonian sexagesimal system employing Arabic numerals, we have established several conventions:

1. A comma "," is used to separate sexagesimal places.
2. A semicolon ";" is used to separate integers from fractions.

Note that these are contemporary conventions. Neither commas nor semicolons have counterparts in ancient texts.

DECIMALLY and SEXAGESIMALLY

For integers:

1 = 1
2 = 2
3 = 3
: etc. :
59 = 59
60 = 1,0
61 = 1,1
: :
119 = 1,59
120 = 2,0
etc.

For fractions:

0.5 = 0;30
0.25 = 0;15
0.75 = 0;45
etc.

In general, then, any sexagesimal expression may be understood in terms of powers of sixty:

The expression 3,15;30 (";" separates integer from fractional part)
means 3 x 60¹ + 15 x 60° + 30 x 60^-1
which means decimally 180 + 15 + .5 = 195.5

Pretty cool, huh?

rah.feb.99

BACK - HOME