Multiplying and Dividing Integers

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Multiplying and Dividing Integers
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At this stage, multiplying and dividing numbers
is an easy task.
8 X 9
15 5
72
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• When we introduce positive and negative signs, a
  series of rules are needed.
• This is where we begin today

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Positive Positive

• (7) X (3)

(21)
(3) X (8)
(24)
With all positives, we can drop the brackets and
signs
7 X 2 14
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Positive Negative
Suppose you borrow 4.00 off of three different
people. How much are you in debt?
Total debt 12 dollars

• (3) X (-4)

(-12)
3 people
Debt of four dollars
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• (3) X (-4)

(-12)
(-5) X (8)
(-40)
Multiplying 2 integers with different signs gives
a negative number.
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Negative Negative
two negatives make a positive WHY?

• (-3) X (-5)

(15)
(-2) X (-5)
(10)
WHY?.
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Consider spending money

• Suppose you spend 10.00 a week on junk food.

How much money have you spent since 3 weeks ago?
You have spent 30 dollars
(Spend 10.00) X (3 weeks ago)
(30)
(-10) X (-3)
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Try these

• (-7) X (-4)

(28)
(16)
(-2) X (-8)
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• The rules for multiplication apply to the process
  of division as well

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• See Sheet