ADDING and SUBTRACTING INTEGERS

INTEGER – all positive and negative whole numbers

ABSOLUTE VALUE – the distance a number is away from zero. So in practice "absolute value" means to remove any negative sign in front of a number, and to think of all numbers as positive

ADDITION:

There are certain rules to remember when adding integers.

 When adding positive integers, the sum will be positive. (This is the same addition you have always done.) (+5) + (+5) = +10

 When adding two negative integers, just add the two integers, and the sum will be negative.

(-8) + (-16) = -24

 When adding integers with different signs (one positive and one negative), follow these steps:

1. Subtract the number with smallest absolute value from the number with largest absolute value,

2. The answer gets the sign of the integer with the largest absolute value.

For example, (+5) + (-10) = I would subtract, 10 – 5 = 5. 10 has a larger absolute value so the answer would be -5. Therefore (+5) + (-10) = -5

In review:

 Positive + positive means add the numbers, your answer is positive

 Negative + negative means add the numbers, your answer is negative

 Positive + negative means subtract the numbers, your answer will have the sign of the largest number

SUBTRACTION:

You DO NOT have to learn a new set of rules for Subtracting Integers;

1. Change all subtraction problems to addition and apply addition rules.

2. Change the sign second number (number being subtracted) to the opposite

- If second number is positive, it becomes negative

- If second number is negative, it becomes positive

For example, 8 – (-2), change the minus to addition and -2 becomes +2, so 8 + 2 = 10. -3 – (+7) -2 – (-10) 5 - 7

-3 + (-7) = -10 -2 + 10 = 8 5 + (-7) = -2