1. Multiplication and Division of Integers

2. Multiplying Positives and Negatives
Hey- your idea was great!
Any idea about multiplying or dividing with negative numbers, please share their thought!

3. The good news!! We get to multiply or divide like normal!
We just need to worry about when it’s a positive or negative solution.

4. Here’s a way I can Remember!
To remember whether your answer will be positive or negative when MULTIPLYING or DIVIDING, we’ll use:
Mr. Multiplivision

5. = -15 What sign is left uncovered? When multiplying
Integers, cover the
Two signs you are using
Choral Response
What sign is left
uncovered?
Ex.: 5 (-3)
Negative, -
That is the sign of
The answer
= -15

6. Practice … under time! (-10)(3) = 21  -5 = -13  -6 =
(raffle tickets…)
(-10)(3) =
21  -5 =
-13  -6 =

7. Division
It’s not any different!
Good News:
Ex.: -48  (-4)
= + 12

8. Reminder:
Equal means it works both ways! 

9. “Boss” and “Secretary”
Person B: Boss first
Partner A: Secretary first
Tell the “secretary” what to write in solving
Copy exactly what boss says
Turn to your neighbor: Person on the left: what’s good about this
Right: What’s the bad consequence of this
Response: They can copy notes, vocab, etc. while holding another conversation, thinking about the weekend, etc.
Cornell notes: questions, summaries
Frayer model- student worded definition
Good News + It”s easy to get their attention with ANY thing different
Think Pair Share
SOLVE:
(4)(-7)  (-2)
Then switch!

10. Grade your boss’ work… Answer: 14 (4)(-7)  (-2) First, (4)(-7) = - 28
Finish it! (-28)(-2)
Answer: 14

11. = 4
(-56  7)  - 2
5  -7  -6
= 210
= - 135

12. Why does it all work?

13. Properties of Multiplication
Identity a  1 = a and 1  a = a
Zero Property a  0 = 0 and 0  a = 0
Property of -1 a(-1) = -a and (-1)a = -a

14. Distributive Property
How will we use this with
integer multiplication?
a (b+c) = ab + bc
-1 (5 + 7) = (-1)5 + (-1)7
Also, -7
= (-1) 7

15. Here’s How to Use It
Ex.: (-7) 6
(-1) (7 6) = - 42

16. (-1)(-1) = ?
= 1
Why??

17. Vocabulary Reciprocal: Two numbers whose product is 1.
Ex.: reciprocal of a:

18. More on Reciprocal
Ex.:
= -2