An integer is a whole number that can be positive, negative, or zero, and does not include a fractional or decimal part. Examples of integers include -5, 1, 5, 8, 97, and 3,043. Some examples of numbers that are not integers are -1.43, 1 3/4, 3.14, .09, and 5,643.1. The set of integers is denoted as Z and is formally defined as follows: Z = {..., -3, -2, -1, 0, 1, 2, 3, ...} . In mathematical equations, unknown or unspecified integers are represented by lowercase, italicized letters from the "late middle" of the alphabet, such as p, q, r, and s. Integers are used in various numbering systems and can be used in real-life situations such as player’s scores in golf, football and hockey tournaments, the rating of movies or songs, and in banks where credits and debits are represented as positive and negative amounts respectively.