Upload
others
View
0
Download
0
Embed Size (px)
Citation preview
CN 24 Multiplying Integers.notebook
1
Multiply Integers (24)
https://www.youtube.com/watch?v=47wjId9k2Hs
https://www.youtube.com/watch?v=K_tPbVPfHgk This video includes division of integers as well. Multiplication and division of integers follow the same rules.
CN 24 Multiplying Integers.notebook
2
Remember: This is how a negative factor is formed.You take a positive integer and multiply it by 1.
CN 24 Multiplying Integers.notebook
3
RulesThe product of two integerswith different signs is negative.
The product of two integerswith the same sign is positive.
SAME rules apply for division.
1)
2)
3)
CN 24 Multiplying Integers.notebook
4
OR
Count up the number of negative signs in the question. Even number of negative signs your answer is positiveOdd number of negative signs your answer is negative.
CN 24 Multiplying Integers.notebook
5
You can think of it this way...
which means: 4 + 4 + 4 = 12
4 x 3 will give you the same result due to the commutative property of multiplication.
positive x negative = negativeThere is an odd number of negative signs so the answer is negative.
There is an odd number of negative signs so the answer is negative.
There is an odd number of negative signs so the answer is negative.
positive x negative = negative negative x positive = negative
There is an odd number of negative signs so the answer is negative.
positive x negative = negative negative x positive = negativeThere is an odd number of negative signs so the answer is negative.
CN 24 Multiplying Integers.notebook
6
THIS IS WHY A NEGATIVE TIMES A NEGATIVE EQUALS A POSITIVE...
5. 7(5)(3)
If there is an odd number of negative signs the answer is negative.
If there is an even number of negative signs the answer is positive.
Think box
If there is an even number of negative signs the answer is positive.
If there is an even number of negative signs the answer is positive.
If there is an even number of negative signs the answer is positive.
If there is an odd number of negative signs the answer is negative.
Note: The base is 4 due to the parenthesis.
CN 24 Multiplying Integers.notebook
7
Try these...
1. 3 x 4
2. 3 x (4)
3. (8)(1)
There is an odd number of negative signs so the answer is negative.
There is an even number of negative signs so the answer is positive.
positive x positive = positivepositive x negative = negative
negative x negative = positive
There is an odd number of negative signs so the answer is negative.
There is an odd number of negative signs so the answer is negative.negative x positive = negative
In this problem, the base is 8 due to the parenthesis. So you take the base and square it.
In this problem, the base is 8. The base is the number directly in front of the exponent. So you take the base and square it. But then you need to remember to take that result and multiply it by 1 due to the negative sign in front of the 8.
base1
8 x 8 = 6464 x 1 = 64
positive x negative = negative
4) 8 x 1
5)
There are no negative signs in this problem.
6)
negative x negative = positive
There is an even number of negative signs so the answer is positive.
CN 24 Multiplying Integers.notebook
8
Ariel says that when multiplying more than two integers with the same sign the product is always positive. Is this true? Explain and give an example.
Write three integers (at least one integer needs to be negative) with a positive product.
Write three integers with a negative product.
CN 24 Multiplying Integers.notebook
9
1. 6(2)(7)
2. 3(3)(4)
3. 2(4)(3)(10)
4. 4(8)(2)(5)
5. 4(5)(7)
6. (2)(3)(4)(1)
Try these...
There is an odd number of negative signs so the answer is negative.
There is an odd number of negative signs so the answer is negative.
There is an even number of negative signs so the answer is positive.
There is an even number of negative signs so the answer is positive.
There is an even number of negative signs so the answer is positive.
There is an even number of negative signs so the answer is positive.
CN 24 Multiplying Integers.notebook
10
What does your answer mean...
Note: Do not write 630 feet below sea level. The word below takes care of the negative sign.
What does your answer mean...
Note:There are12 monthsin a year.
There is an odd number of negative signs so the answer is negative.
negative x positive = negative
There is an odd number of negative signs so the answer is negative.
negative x positive = negative
CN 24 Multiplying Integers.notebook
11
Try these...
Evaluate the expression: 2a b if a = 3 and b = 5
if a = 5 and b = 8Evaluate the expression: 3b a2
Remember the rules for PEMDAS
keep add opposite
There is an even number of negative signs so the answer is positive
Think box:
There is an even number of negative signs so the answer is positive
negative x positive = negative
192 + 25
keep add opposite
CN 24 Multiplying Integers.notebook
12
Note: There are two circumstances...
There is an odd number of negative signs so the answer is negative.
negative x positive = negativeThere is an odd number of negative signs so the answer is negative.
Multiply 3 by itself 3 timesThere is an odd number of negative signs so the answer is negative.
There is an odd number of negative signs so the answer is negative.
positive x negative = negative
What does your answer mean...
CN 24 Multiplying Integers.notebook
13