1. 1.5 Adding/Subtracting Numbers Absolute Value: The distance of a number from 0 on the number line. Additive Inverse: A given number and its opposite.

2. Deductive Reasoning: The numbers that are the same distance from 0 on the number line but lie in opposite directions. Opposites: The numbers that are the same distance from 0 on a number line but lie in opposite directions.

3. GOAL:

4. We can add or subtract any real numbers using the number line model: Ex: What is each sum? Use a number line A) 3 + 5 B) 3 + (-5) = 8 = - 2

5. C) - 3 + 5 D) 3 + (-5) = 2 = - 8

6. | absolute value | = the distance the number is from zero on the number line | -5 | = 5 and | 5 | = 5

7. Key Concept:

8. In math we always translate English words into symbols: 1. (+) = add, plus, added to: 3 plus 5  3 + 5 2. (-) = minus, subtract, less than: 3 minus 5  3 - 5

9. 3. (x) = multiply, times, product of: the product of 3 and 5  (3)5 4. (/) = division, quotient, fraction: The quotient of 3 and 5  3/5

10. Key Concept:

11. When you add + with – sign  the biggest number rules (takes the sign) 5 + (-20) = 5 – 20 = -15 and - 5 + 20 = -5 + 20 = 15 Remember:

12. REAL-WORLD: A MAC student has to attend school from 8:00 am to 3:45 pm. A band student has to practice for a total of 1.5 hrs. and spend at least 2 hrs. doing the classes assigned research. Represent this situation using a number line to show how many hours the students has left for other house shores.

13. Solution: 24 hrs. in a day  24 School 8:00-3.45 say 4:00 pm  - 8 hrs.

14. Solution: 1.5 hrs. practice  - 1.5 2 hrs. research  - 2

15. Solution: Don’t forget sleep  - 8 if possible Thus: A students cannot afford to spend time playing games!

16. YOU TRY IT: Use the number line to find the sum of: - 6 + ( - 7)

17. SOLUTION: Start at -6 And move 7 to the left ( - 7) Therefore – 6 + ( - 7 ) = -13

18. VIDEOS: Addition and Subtraction Negatives: http://www.khanacademy.org/math/arithmetic/abs olute- value/adding_subtracting_negatives/v/negative- numbers-introduction

19. CLASSWORK: Page 33-36: Problems: As many as it takes you to master the concept