Method of writing numerals to represent numbers.
The use of zero as a placeholder was the greatest advance in number systems. The most common system is the decimal system, in which 10 symbols (the Hindu-Arabic numerals ) denote multiples of powers of 10 by their position relative to the decimal point. Computers have brought greater awareness of the binary number system, in which two symbols, 0 and 1, represent multiples of powers of 2.