An integer is a whole number that is not a fraction. Integers include both positive and negative numbers, and there are several rules for adding integers.

Adding two positive integers together will always result in a positive integer. For example, 6 + 4 = 10. To add two negative integers, add the numbers together and place a negative sign in front of the answer. For example, -12 + (-4) = -16. To add a negative integer and a positive integer, subtract the negative integer from the positive integer. For example, -4 + 9 = 9 - 4 = 5. If the negative integer has a higher number value than the positive integer, subtract the smaller value from the larger and put a negative sign in front of the answer. For example, -16 + 6 = -10.