today’s lesson: what: multiplying and dividing integers why: to establish the rules for...
TRANSCRIPT
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: