1. Subtracting Integers Objective: Learn to subtract integers.

2. When subtracting integers: 5 - 3 = 2 When you see the exercise above, you might think you are just subtracting two positive numbers. Now you can also see this exercise as a positive and negative number. So, we should follow the addition integer rules. 5 - 3 = 2

3. When you have two negative numbers shown like this: -7 – 8 You have to follow the addition rules as if they were two negative numbers and change as follows: -7 + (- 8) = We will follow the addition rules… For example: - 6 - 7 = you change it as follows… -6 + (-7)= so you add and the answer is negative. Example: – 10 – 7 =

4. Ex. 6 - 15 = you must change it as follows: 6 + (-15)= So you have a positive and a negative number. Follow the addition rules:. When adding a positive and negative number you must SUBTRACT and the answer takes the sign of the larger number. So the answer is – 9 Your example: 12 – 26 = When subtracting integers:

5. Watch out! Whenever you see 2 negative signs together, you must turn them both into positives! For Ex. - (- a ) = + a  When you subtract a negative number… For example: 1 – (– 2) = You must change the subtraction to an addition and the negative to a positive… Like this: 1 + (+2) = 3 Example 1: 4 – (- 19) = Example 2: - 11 – (- 42) =

6. Summary Adding and Subtracting Integers 1. + + + = add (+) 2. - + - = add ( - ) 3. - + or + - = subtract and… the answer takes the sign of the larger number. 4. When you see 2 negative signs together, with no number in the middle….you must turn them BOTH into positive!! - (- ) + (+ )

7. Homework: Solve. Follow the adding and subtracting integer rules.