1. Rules of adding integers

2. SOLVE
The highest elevation in North America is Mt. McKinley, which is 20,320 feet above sea level. The lowest elevation is Death Valley, which is 282 feet below sea level. What is the distance from the top of Mt. McKinley to the bottom of Death Valley?

3. SOLUTION
The distance from the top of Mt. McKinley to the bottom of Death Valley is the same as the distance from +20,320 to -282 on the number line. We add the distance from +20,320 to 0, and the distance from 0 to -282, for a total of 20,602 feet.

4. Positive & Negative Numbers
Working with positive and negative numbers is like driving in traffic. You have to watch the traffic signs and follow the driving rules.

5. Integer Addition Rules
Rule #1 – Sum of two positive integers is always positive
4 + 1 = 5 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6

6. Integer Addition Rules
Rule #2 – Sum of two negative integers is always negative. = -6 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6

7. Hint
If you don’t see a negative or positive sign in front of a number it is positive. 9 +

8. Integer Addition Rules
Rule #3 – Sum of a positive and a negative integer could be positive, negative, or zero. Subtract the smaller from the larger one and put the sign of the larger one in front of your answer.
-5 + (+9) = 4 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6

9. Your Turn = -2 + 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6 -

10. Your tURN = -4 + 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6 -

11. Your Turn = -5 - 1 2 3 4 5 6 -1 -2 -3 -4 -5 -6 -

12. Excellent!
Finish your worksheet