1. Quick Review Find each sum: 1. 5 + 5 + 5 + 5 + 5 2.(-3) + (-3) + (-3) Answers: 1.25 2.-9

2. Multiplying and Dividing Integers Section 1-8 (page 45-49)

3. Rules To multiply a positive and negative integer, think of multiplication as repeated addition. Example: A cave explorer descends 4ft/min for 3 minutes. 3 (-4) = (-4) + (-4) + (-4) = -12

4. Rules You can use number lines to multiply integers. 3(2) means three groups of 2. -6 -4 -2 0 2 4 6 +2 +2 +2

5. Rules The product of two integers with the same sign is positive. 3(2) = 6-3(-2) = 6 The product of two integers with different signs is negative. 3(-2) = -6-3(2) = -6

6. Find each sum… 1. 5(3) 2. 5(-3) 3. -5(3) 4. -5(-3) 15 -15 15 same sign, positive product different sign, negative product same sign, positive product

7. Additional Problems 1. -6 * (2)= 2. 15 * (-8) = 3. -12 * (-6) = 4. - 7 ÷ (-1) = -120 -12 72 7

8. Rules The quotient of two integers with the same sign is positive. 10 ÷ 2 = 5 -10 ÷ (-2) = 5 The quotient of two integers with different signs is negative. -10 ÷ 2 = -5 10 ÷ (-2) = -5

9. Find each quotient… 1. 12 ÷ 2 2. -12 ÷ 2 3. 12 ÷ (-2) 4. -12 ÷ (-2) 6 -6 6 same sign, positive product different sign, negative product same sign, positive product

10. Additional Problems 1. 14 ÷ (-2) = 2. -32 ÷ (-8) = 3. -56 ÷ (-7) = 4. - 121 ÷ 11 = 4 -7 -11