* Egyptian System - the numbers 1-9 as vertical lines, the number 10 as U or circle, the number 100 as a coiled rope, and the number 1,000 as lotus blossom.

* The first numbering systems similar to those in use today were invented between 100 and 200 A.D. by Hindus in India who created a nine-digit numbering system.

* Around 875 A.D., the concept of zero was developed.