Today’s Lesson:

What: Multiplying and dividing integers

Why: To establish the rules for multiplying and dividing integers.

3(-3) = -9

MODELS FOR Multiplying INTEGERS:

2(____) = -10

Three groups of negative 3 is -9!

Two groups of negative 5 is -10!

-- - -

--

MODEL FOR dividing INTEGERS:

-6 ÷ _____ = -3

What other problem is this a model of ???

Answer: 2(-3) = -6

Rules for multiplying And dividing integers:

SAME SIGNS

_____________ ANSWER

3 ● 4 = 12 -3 ●-4 = 12

DIFFERENT SIGNS

_____________ ANSWER

-3 ● 4 = -12 3 ● -4 = -12

POSITIVE NEGATIVE

6 ÷ 3 = 2-6 ÷ -3 =2

-6 ÷ 3 = -2

6 ÷ -3 = -2

Multiplication/ division memory “tricks”:

P N N

N P N

N N P

Make a Tic-Tac-Toe Board with “P’s” in the diagonal and “N’s” in all the otherspaces. Read board in any direction—up, down, left, right, diagonal– from the outside in, and it will give you the rightanswer.

P= positive N= negative

Fill in your letters . . .

Smiley Face Method: Smile = _________________ answer

Frown =_________________ answer

We like to sleep!

We don’t like to be hit in the eye!

+ + - - - +

POSITIVE

NEGATIVE

+ -

Evaluate the following examples:1. 8(-6) = 2. -12(-4) = 3. -11 ∙ 7 =

4. 48 ÷ - 4 = 5. -28/-7 = 6. 150/ -5 =

7. 21(-8) = 8. -56/8 = 9. 25.2 ∙ 3.5 =

-48 48 -77

-12 4 -30

-168 -7 88.2

END OF LESSON

The next slides are student copies of the notes for this lesson. These notes were handed out in class

and filled-in as the lesson progressed.

NOTE: The last slide(s) in any lesson slideshow (entitled “Practice Work”)

represent the homework assigned for that day.

MODELS FOR Multiplying INTEGERS:

Math-7 NOTES DATE: ______/_______/_______What: Multiplying and dividing integers Why: To establish the rules for multiplying and dividing integers.

NAME:

2(____) = -10

3(-3) = -9

Three groups of negative 3 is -9!

Two groups of negative 5 is -10!

Rules for multiplying And dividing integers:

SAME SIGNS

________ ANSWER

3 ● 4 = 12-3 ● -4 = 12

DIFFERENT SIGNS

_________ ANSWER

-3 ● 4 = -123 ● -4 = -12

MODEL FOR DIVIDING INTEGERS:

-- - -

-- -6 ÷ _____ = -3

What other problem is this a model of ???

6 ÷ 3 = 2-6 ÷ -3 = 2

-6 ÷ 3 = -26 ÷ -3 = -2

Multiplication/ division memory “tricks”:

+ + - ++ -- -

Evaluate the following examples:1. 8(-6) = 2. -12(-4) = 3. -11 ∙ 7 =

4. 48 ÷ - 4 = 5. -28/-7 = 6. 150/ -5 =

7. 21(-8) = 8. -56/8 = 9. 25.2 ∙ 3.5 =

Make a Tic-Tac-Toe Board with “P’s” in the diagonal and “N’s” in all the otherspaces. Read board in any direction—up, down, left, right, diagonal– from the outside in, and it will give you the rightanswer.

Smiley Face Method: Smile = __________ answer

Frown= __________ answer

We like to sleep! We like to sleep!We don’t like to be hit in the eye!

P= positive N= negative

Math-7 PRACTICE DATE: ______/_______/_______NAME:__________________________

“multiply/ divide INTEGERS”Multiplication:

Division: