The BRAHMI NUMERALS are a numeral system attested from the 3rd century BCE (somewhat later in the case of most of the tens). They are the direct graphic ancestors of the modern Indian and Hindu–Arabic numerals . However, they were conceptually distinct from these later systems, as they were not used as a positional system with a zero . Rather, there were separate numerals for each of the tens (10, 20, 30, etc.). There were also symbols for 100 and 1000 which were combined in ligatures with the units to signify 200, 300, 2000, 3000, etc.
The source of the first three numerals seems clear: they are
collections of 1, 2, and 3 strokes, in Ashoka 's era vertical I, II,
Roman numerals , but soon becoming horizontal like the modern
Chinese numerals . In the oldest inscriptions, 4 is a +, reminiscent
of the X of neighboring
Kharoṣṭhī , and perhaps a representation
of 4 lines or 4 directions. However, the other unit numerals appear to
be arbitrary symbols in even the oldest inscriptions. It is sometimes
supposed that they may also have come from collections of strokes, run
together in cursive writing in a way similar to that attested in the
development of Egyptian hieratic and demotic numerals, but this is not
supported by any direct evidence. Likewise, the units for the tens are
not obviously related to each other or to the units, although 10, 20,
80, 90 might be based on a circle.
The sometimes rather striking graphic similarity they have with the hieratic and demotic Egyptian numerals, while suggestive, is not prima facie evidence of an historical connection, as many cultures have independently recorded numbers as collections of strokes. With a similar writing instrument, the cursive forms of such groups of strokes could easily be broadly similar as well, and this is one of the primary hypotheses for the origin of Brahmi numerals.
Another possibility is that the numerals were acrophonic , like the
* Georges Ifrah, The Universal History of Numbers: From Prehistory to the Invention of the Computer. Translated by David Bellos, Sophie Wood, pub. J. Wiley, 2000. * Karl Menninger (mathematics) , Number Words and Number Symbols - A Cultural History of Numbers ISBN 0-486-27096-3 * David Eugene Smith and Louis Charles Karpinski , The Hindu-Arabic Numerals (1911)