1. Adding and Subtracting Real Numbers

2.  5 + 7 (Since both numbers are both positive just add)  5 + 7 = 12  -3 + (-6) (Since both numbers are negative the answer is a larger negative)  -3 + (-6) = - 9

3. Adding and Subtracting Real Numbers  What do you do if opposite signs????? Whatever sign is the larger number, the answer will carry this sign!!!!!  7 + ( -10) Which Number is the larger number?  7 + (-10) Since the -10 is the larger number your answer will be negative  7 – 10 = -3 Because you know the back number is negative subtract  -12 + 4 Which Number is the larger number?  -12 + 4 Since the -12 is the larger number your answer will be negative  -12 + 4 = -8 or rewrite 4 -12 = -8

4. Adding and Subtracting Real Numbers  1. -7 + 11  -7 + 11 = 4 or 11 – 7 = 4  2. 15 + (-11)  15 + (-11) = 4 or 15 – 11 = 4  3. -5 + (-3)  -5 + (-3) = -8  4. -15 + 7  -15 + 7 = - 8 or 7 – 15 = -8

5. Adding and Subtracting Real Numbers  11 - 7  11 - 7 = 4  - 7 – (-3) Every negative after 7 belongs to the 3.  One negative sign = a negative (-) sign  Two negative signs = a positive sign  - 7 – (-3) = - 7 + 3 = -4 or 3 -7 = -4

6. Adding and Subtracting Real Numbers  9 – (-6) Every negative after 9 belongs to the 6.  How many negative? Is the 6 positive or negative  9 - (-6) = 9 + 6  9 + 6 = 15  10 – 12  10 – 12 = -2

7. Adding and Subtracting Real Numbers  -14 – 5 Are both numbers negatives?  -14 - 5 = -19  7 - (-12) How many negatives does 12 have????  7 + 12 The 12 has two – signs and becomes (positive) 12  7 + 12 = 19  -4 - (-8) How many negatives does 8 have????  -4 + 8 Since signs are opposite, which number is larger?  -4 + 8 = 4 or 8 – 4 = 4

8. Word Problems  Mark is flying in an airplane. The plane is cruising at 5700 feet above sea level. The plane hits turbulance and drops 750 feet before the pilot climbs 300 feet.  A. Write an equation showing the math to this problem.  B. What height is the plan now?

9. Word Problems  Mark is flying in an airplane. The plane is cruising at 5700 feet above sea level. The plane hits turbulance and drops 750 feet before the pilot climbs 300 feet.  A. Write an equation showing the math to this problem.  5700 - 750 + 300  B. What height is the plan now?  5700 - 750 + 300 = 5250 feet

10. Word Problem  Phil is in Minnesota. The temperature is 10 below zero. Over night, the temperature drops another 12 degrees before midnight, and raises 8 degrees before noon.  A. Write an equation showing the math to this problem.   B. What is the temperature now? 

11. Word Problem  Phil is in Minnesota. The temperature is 10 below zero. Over night, the temperature drops another 12 degrees before midnight, and raises 8 degrees before noon.  A. Write an equation showing the math to this problem.  -10 - 12 + 8  B. What is the temperature now?  -10 - 12 + 8 = -14  The temperature is now -14 degrees

12. Word Problem  Darnell is scuba diving. He is 400 feet below the his boat when he sees a shark. He swims 100 feet up into a school of fish and then swims 75 feet down to see a sea turtle.  A. Write an equation showing the math to this problem.   B. How many feet above or below the sea is Darnell? 

13. Word Problem  Darnell is scuba diving. He is 400 feet below the his boat when he sees a shark. He swims 100 feet up into a school of fish and then swims 75 feet down to see a sea turtle.  A. Write an equation showing the math to this problem.  -400 + 100 - 75  B. How many feet above or below the sea is Darnell?  -400 + 100 - 75  He is 375 feet below sea level or -375

14. Word Problem  Jose has $1250 in his check account. He pays $750 for rent, $125 for his cell phone, $85 for car insurance. He friend Candy pays him $75 for concert tickets.  A. Write an equation showing the math to this problem.  B. How much money does Jose have in his account? 

15. Word Problem  Jose has $1250 in his check account. He pays $750 for rent, $125 for his cell phone, $85 for car insurance. He friend Candy pays him $75 for concert tickets.  A. Write an equation showing the math to this problem.  1250 – 750 – 125 - 85 + 75  B. How much money does Jose have in his account?  1250 – 750 – 125 - 85 + 75  He has $365 in his account

16. Adding and Subtracting Real Numbers Practice Problems  1. 15 + (-7)  2. -9 + 4  3. -7 + (-3)  4. 5 - (-7)  5. -15 - 9  6. 9 - (-2)  7. -11 + 6 - 3  8. 17 + (-6) - 8  9. 18 - (-12)  10. -13 - (-17)

17. Adding and Subtracting Real Numbers Practice Problems Answers  1. 15 + (-7) = 22  2. -9 + 4 = -5  3. -7 + (-3) = -10  4. 5 - (-7) = 12  5. -15 - 9 = -24  6. 9 - (-2) = 11  7. -11 + 6 - 3 = -8  8. 17 + (-6) - 8 = 3  9. 18 - (-12) = 30  10. -13 - (-17) = 4