Multiplying and Dividing Integers

1. Multiplying and Dividing Integers We are learning to…multiply and divide integers by looking for patterns. Tuesday, August 30, 2011

2. Multiplication of Integers -8 Evaluate: -2 + -2 + -2 + -2 = ________ Repeated addition is the same thing as:__________________ ...so -2 + -2 + -2 + -2 can be written:________ Evaluate: -4 + -4 + -4 = ______________ Repeated addition is the same thing as:__________________ . ..so -4 + -4 + -4 can be written:________ Multiplication 4(-2) -12 Multiplication 3(-4)

3. Multiplication of Integers -35 Evaluate: -7 + -7 + -7 + -7 + -7 = ______________ ...Rewrite as a multiplication problem:_________ Evaluate: -12 + -12 = ______________ ...Rewrite as a multiplication problem:_________ Evaluate: -1 + -1 + -1 + -1 + -1 = ______________ ...Rewrite as a multiplication problem:_________ 5(-7) -24 2(-12) -5 5(-1)

4. Multiplication of Integers I know that: (positive number) × (negative number) = _______________________________________. The ______________________________ property of multiplication allows me to multiply in any order. So I also know that (negative number) × (positive number) = _______________________________________. Negative Number Commutative Negative Number Evaluate the expressions below. When your entire group is finished share your solutions.

5. Multiplication of Integers Negative Negative Negative × Positive = _______________ and Positive × Negative = _______________ If the signs in a multiplication problem are different the solution is:_______________ I know that a: positive × positive = ______________ Now follow the pattern: (+)(–) = ______________ (–)(+) = ______________ (+)(+) = ______________ So… (–)(–) = ______________ I know that a: negative × negative = _________________________ If the signs in a multiplication problem are the same the solution is:_______________ Negative Positive Negative Negative Positive Positive Positive Positive

6. 7(-8) = _____ • 56 • -56 • -1 • -15 • I need help with this question.

7. -6(-7) = _____ • 49 • -42 • -13 • 42 • I need help with this question.

8. -9(3) = _____ • 27 • -6 • -36 • -27 • I need help with this question.

9. Which of the following statements is not true? • A negative multiplied by a negative is a positive product. • A positive multiplied by a negative is a negative product. • A negative multiplied by a negative is a negative product. • A negative multiplied by a positive is a negative product. • I need help with this question.

10. Division of Integers c b a then The Division Algorithm: If Example 1: Negative divided by a Positive: -8 -8 so… or… Negative • Negative divided by a positive will always result in a:______________

11. Division of Integers c b a then The Division Algorithm: If Example 2: Positive divided by a Negative: -7 -7 so… or… Negative • Positive divided by a negative will always result in a:______________

12. Division of Integers c b a then The Division Algorithm: If Example 2: Negative divided by a Negative: 6 6 so… or… Positive • Negative divided by a negative will always result in a:______________

13. Division of Integers Wait a minute…these look familiar! These are the same rules as:____________________________ If the signs in a division problem are different the solution is:______________ If the signs in a division problem are the same the solution is:_____________ Multiplication Negative Positive

14. Evaluate: • 8 • -8 • 7 • -9 • I need help with this question.

15. Evaluate: • 21 • -20 • -22 • -21 • I need help with this question.

16. Evaluate: • -7 • 7 • 8 • -6 • I need help with this question.