Mathematics For Computer Science - Integers

​Integers
Integers are negative and positive whole numbers, again including 0. The symbol ℤ is
used for the set of integers, so that ℤ = {…, –3, –2, –1, 0, 1, 2, 3, …}. ℤ is used for integers
because ‘Zahlen’ is German for ‘numbers’.
Just as with natural numbers, if a member of ℤ is added to or multiplied by another
member of ℤ, the result is also a member of ℤ. This is also true for subtraction as ℤ
includes the negative whole numbers. Integers are therefore very useful as counters in
computer programs for whole quantities that may be negative.