Definition
Integer
An integer is zero, a positive whole number, or a negative whole number.
What it means
Think of evenly spaced landing spots on a number line. Every spot marked with a counting number, its opposite, or zero is an integer. You can move left into negative integers or right into positive integers, but a value between the spots, such as 2½, is not an integer.
Remember it
Integers are the full steps on a number line—no stopping between steps.
Example
A game score starts at 4 and then loses 7 points: 4 − 7 = −3. The starting score 4, the change −7, and the result −3 are all integers.
Watch for
Fractions and non-whole decimals are not integers. A decimal notation can still name an integer when its value is whole: 2.0 = 2.
Common mix-up
Zero is an integer. Integers are not only the positive counting numbers.
Exact meaning
An integer is any number in the set …, −3, −2, −1, 0, 1, 2, 3, …: zero, a positive whole number, or the negative of a positive whole number.