Zero Zero shows that there is no amount. Example: 6 − 6 = 0 (the difference between six and six is zero) It is also used as a "placeholder" so we can write a numeral properly. Example: 502 (five hundred and two) could be mistaken for 52 (fifty two) without the zero in the tens place., 0 is the integer that precedes the positive 1, and follows −1. In most (if not all) numerical systems, 0 was identified before the idea of 'negative integers' was accepted., Zero, or 0, is a number and the numerical digit used to represent the number 0 is widely used in mathematics, and can be used as a number in its own right, or as a placeholder in equations., Zero is the integer denoted 0 that, when used as a counting number, means that no objects are present. It is the only integer (and, in fact, the only real number) that is neither negative nor positive., The Origins of the Zero Overview The zero was invented three times in the history of the mathematics. The Babylonians, the Maya, and the Hindus all invented a symbol to represent nothing. However, only the Hindus came to understand the importance of what the zero represented. Today we use a descendant of the Hindu zero, which had a long journey and encountered much resistance until finally , Simple answer: 0! (read "Zero Factorial") is defined to equal 1. Involved answer (s): There are several proofs that have been offered to support this common definition. Example (1) If n! is defined as the product of all positive integers from 1 to n, then: 1! = 1*1 = 1 2! = 1*2 = 2 3! = 1*2*3 = 6 4! = 1*2*3*4 = 24 n! = 1*2*3** (n-2)* (n .