1. copyright©amberpasillas2010

2. You have learned lots of things about adding and subtracting integers. Let’s review addition !

3. copyright©amberpasillas2010 If the signs are the same Take the sum of the numbers. The sign stays the same. 4 + 2 = -4 + -2 = + + + ++ + 6 _ _ _ __ _ -6

4. copyright©amberpasillas2010 If the signs are different Take the difference of the numbers. Subtract the smaller number from the larger one. The larger number carries the sign. -9 + 4 = 9 - 4 = 5 Subtract the numbers - 5 _ _ _ _ + + + + _ _ _ _ _ Answer -5 because you started with more negatives

5. copyright©amberpasillas2010 Keep the first number and add the opposite. 5 – 6 Is the same as = -1 4 – ( – 2)Is the same as4 – (– 2) = 6 -3 – 1 Is the same as -3 – ( 1) = -4 * SUBTRACT = PLUS CHANGE!

6. copyright©amberpasillas2010 Discuss with a partner ways that you know that the problem is solved correctly. 6 – (-9) = 15

7. copyright©amberpasillas2010 Subtracting a negative number is the same as adding a positive. Change the signs and add. 2 – (-7) is the same as 2 + (+7) 2 + 7 = 9!

8. copyright©amberpasillas2010 Here are some more examples 8 – 4 Is the same as = 4 6 – ( – 1)Is the same as6 – (– 1) = 7 -5 – 3 Is the same as -5 – ( 3) = -8 * SUBTRACT = PLUS CHANGE! -8 – (-6) Is the same as -8 – (-6) = -2

9. copyright©amberpasillas2010 Say These Together! 8 – (-12) 8 + (+12) 22 + (+30) 22 – (-30) = 20 = 52

10. copyright©amberpasillas2010 Say These Together! -17 – (-3) -17 + (+3) -10 + (-5) -10 – 5 = -14 = -15

11. copyright©amberpasillas2010 Try These! Solve: 3 – 10 Solve: 17 – (– 12) = -7 = 29

12. copyright©amberpasillas2010 Try These! -3 + 5 = -3 - 5 = +3 + 5 = +3 - 5 = +2+2 -8 +8+8 -2

13. copyright©amberpasillas2010 Try These! -15 + 6 = -15 - 6 = +15 + 6 = +15 - 6 = -9 -21 +21 +9+9

14. copyright©amberpasillas2010 Try These! -2 + 9 = -2 - 9 = +2 + 9 = +2 - 9 = +7+7 -11 +11 -7

15. copyright©amberpasillas2010 Try These! -5 + 8 = -5 - 8 = +5 + 8 = +5 - 8 = +3+3 -13 +13 -3

16. copyright©amberpasillas2010 Aren’t integers interesting? TAKE OUT YOUR STUDY GUIDE

17. copyright©amberpasillas2010 Subtracting Integer Rules Keep the first number and add the opposite. 5 – 6 Is the same as = -1 4 – ( – 2)Is the same as4 – (– 2) = 6 -3 – 1 Is the same as -3 – ( 1) = -4 #10 * SUBTRACT = PLUS CHANGE!

18. EXTRAS: You can use them the next day when going over homework corrections. copyright©amberpasillas2010

19. HOMEWORK EXPLANATION ADD INTEGERS -8 + 5 = 8 – 5 = 3 RULE: Subtract the numbers - 3 _ _ _ _ _ + + + + + _ _ _ Answer -3 because you started with more negatives SUBTRACT INTEGERS 3 – -2 = 5 + + + – – + + -3 – 2= -5 _ _ _ + + _ _ RULE: Add the opposite! 3 – -2= 5 -3 – 2= -5

20. copyright©amberpasillas2010 1) -6 + 8 = 2) -9 - 7 = 3) +5 + 8 = 4) -16 + 10 = 5) 13 - 5 = 6) -2 - 7 = 7) 6 + -20 = 8) -7 + -12 = +2 -16 13 -6 8 -9 -14 -19 9) -3 - 8 = 10) 12 - 18 = 11) +26 - 4 = 12) -19 + 4 = 13) 6 - 10 = 14) -2 + 16 = 15) +5 + 4 = 16) -19 + 6 = -11 -6 22 -15 -4 14 9 -13

21. copyright©amberpasillas2010 Evaluate The Expression Evaluate means to find the value of an algebraic expression by substituting numbers in for variables. m = -2 8 + m ? 8 + -2 6

22. copyright©amberpasillas2010 Evaluate The Expression Evaluate means to find the value of an algebraic expression by substituting numbers in for variables. r = -3 7 – r ? 7 – -3 10

23. copyright©amberpasillas2010 Evaluate The Expression Evaluate means to find the value of an algebraic expression by substituting numbers in for variables. Evaluate the variable expression when n = 6 1)2)

24. copyright©amberpasillas2010 Evaluate The Expression Evaluate means to find the value of an algebraic expression by substituting numbers in for variables. Evaluate if a = -3, b = -4, and c = 2 12 – a + b – c 12 – (-3) + (-4) – (2) 15 + -4 – 2 11– 2 9 # Extra