The English is a bit crappy, but it will do.
The invention was done, according to what I understand of the last line, of these numerals is 792 AD.
Here's a whole book about it (184 pages):
The Hindu-Arabic numerals (1911)
Smith, David Eugene, 1860-1944; Karpinski, Louis Charles, 1878-1956, joint author
Edited by Abramelin, 05 February 2012 - 06:10 PM.