Definition:Babylonian Number System

Definition
The number system as used in the was a positional numeral system where the number base was a combination of decimal (base $10$) and sexagesimal (base $60$).

The characters were written in by a combination of:
 * a thin vertical wedge shape, to indicate the digit $1$
 * a fat horizontal wedge shape, to indicate the digit $10$

arranged in groups to indicate the digits $2$ to $9$ and $20$ to $50$.


 * Babylonian symbols.gif

At $59$ the pattern stops, and the number $60$ is represented by the digit $1$ once again.

Thus these groupings were placed side by side:
 * the rightmost grouping would indicate a number from $1$ to $59$
 * the one to the left of that would indicate a number from $60 \times 1$ to $60 \times 59$

and so on, each grouping further to the left indicating another multiplication by $60$

For fractional numbers there was no actual radix point. Instead, the distinction was inferred by context.

The fact that they had no symbol to indicate the zero digit means that this was not a true positional numeral system as such.

For informal everyday arithmetic, they used a decimal system which was the decimal part of the full sexagesimal system.