1. Add. 1. –7 + 24. –6 + (–28) 2. –12 + (–9) 5. 104 + (–87) 3. 32 + (–19) 6. –18 + (–24) Bell Work –5–34 17 –42 –21 13

2. Problem of the Day Copy and complete the magic square. The magic sum is 0. –8+3 –20 –3 +5 +2 –5+8

3. Subtracting Integers

4. Subtracting a smaller number from a larger number is the same as finding how far apart the two numbers are on a number line. Subtracting an integer is the same as adding its opposite. SUBTRACTING INTEGERS WordsNumbersAlgebra Change the subtraction sign to an addition sign and change the sign of the second number. 2 – 3 = 2 + (–3) 4 – (–5) = 4 + 5 a – b = a + (–b) a – (–b) = a + b

5. What’s the difference between 7 - 3 and 7 + (-3) ? 7 - 3 = 4 and 7 + (-3) = 4 The only difference is that 7 - 3 is a subtraction problem and 7 + (-3) is an addition problem. “SUBTRACTING IS THE SAME AS ADDING THE OPPOSITE.” “SUBTRACTING IS THE SAME AS ADDING THE OPPOSITE.”(Keep-change-change)

6. When subtracting, change the subtraction to adding the opposite (keep-change-change) and then follow your addition rule. Example #1: - 4 - (-7) - 4 + (+7) Diff. Signs --> Subtract and use larger sign. 3 Example #2: - 3 - 7 - 3 + (-7) Same Signs --> Add and keep the sign. -10

7. Which is equivalent to -12 – (-3)? 1. 12 + 3 2. -12 + 3 3. -12 - 3 4. 12 - 3 Answer Now

8. 7 – (-2) = ? 1. -9 2. -5 3. 5 4. 9 Answer Now

9. The top of the Sears Tower in Chicago, is 1454 feet above street level, while the lowest level is 43 feet below street level. How far is it from the lowest level to the top? 1454 – (–43) Subtract the lowest level from the height. 1454 + 43 Add the opposite of ( – 43). = 1497 Same sign; use the sign of the integers. It is 1497 feet from the lowest level to the top.

10. The distance from the high dive to the swimming pool is 10 feet. The pool is 12 feet deep. What is the total distance from the high dive to the bottom of the pool? 10 – (–12) Subtract the depth of the pool from the height of the high dive. 10 + 12 Add the opposite of ( – 12). = 22 Same sign; use the sign of the integers. It is 22 feet from the diving board to the bottom of the pool.

11. 1) If the problem is addition, follow your addition rule. 2) If the problem is subtraction, change subtraction to adding the opposite ( keep-change-change ) and then follow the addition rule. Review

12. Absolute Value of a number is the distance from zero. Distance can NEVER be negative! The symbol is |a|, where a is any number.

13. Examples 7=7= 7 10 100  10  =  -100  =  5 - 8  =  -3  = 3

14. |7| – |-2| = ? 1. -9 2. -5 3. 5 4. 9 Answer Now

15. |-4 – (-3)| = ? 1. -1 2. 1 3. 7 4. Purple Answer Now

16. Practice:  Green Book: pg.65 #11-21