Schneibster said:
The Arabs invented the idea of having a numeral for zero, and also invented the idea of giving numerals a value based on their place within a number; zero signified places for which there was no value needed to define the number, just as they do today.
Schneibster is propagating a myth; the Arabs did not invent either the zero, or the place-value notation. They first started using the Greek numbering system, which started at alpha (1), beta (2), and so on including the archaic digamma, until theta (9), then iota (10), kappa (20) until the archaic koppa (90) excluding san, rho (100) to omega (800) and the archaic san (900). Up until the twelfth century, the Arabs used this system, either by transposing it on their own letters or directly using Greek characters. By the ninth century one variant started to gain popularity, with the numbers up to 400 (from the 22 Hebrew or Syriac letters) mapped onto the alphabet with 500, 600, ..., 1000 from the Byzantines.
This system was purely additive. for instance, 472 would have been expressed ta (400) ayn (70) ba (2). This had a major drawback; it was difficult to express numbers larger than 1000. For 10,000 the letter ghayn would have to be repeated ten times. To get over that, a hybrid system (again possibly borrowed from the greeks) was devised, with a letter in front of the ghayn denoting a multiplication, hence dal (4) ghayn (1000) meaning 4 x 1000, and thus dal ghayn ta ayn ba would be 4 x 1000 + 400 + 70 + 2. This can also still be found in English, the Gettysburg Address being the classic example: 'Four score and seven years ago...' (4 x 20 + 7).
This was the system most Arabs used, though in learned circles another system was introduced by Mohammed ibn Musa al-Khowarizmi. His book survived only in the Latin translation, where he was called Algorismi. (Another book of his, Al-jabr w'al-muqabalah, gave rise to the word algebra). This was where our place-value notation comes from. The Arabs did not invent it, though they did introduce it to the Europans. This system used nine symbols, eka (1), dvi (2), tri (3), catur (4), panca (5), sat (6), sapta (7) asta (8), nava (9), with which they could express arbitrarily large numbers, going with powers of ten. This, however, required columns, which could be eliminated if a symbol was added to denote an empty column, which was either a circle or a dot.
Originally, this symbol represented merely an empty column, and only later did the Indians used it to denote a null value.
The Babylonians, Chinese and the Mayans also independently came up with a place-value notation, but the Chinese lacking a symbol for 0, which was introduced to them by the Indians.
(Source: Georges Ifrah, From One to Zero. Highly recommended)