0 (number)

0 (zero) is both a number and a numerical digit used to represent that number in numerals. It plays a central role in mathematics as the additive identity of the integers, real numbers, and many other algebraic structures. As a digit, zero is used as a placeholder in place value systems. Historically, it was the last digit to come into use. In the English language, zero may also be called null or nil when a number, "oh" (IPA: ) or cipher (archaic) when a numeral, and nought or naught in either context.