Operations with Integers

1
Operations with Integers
2
Operations

• There are 4 ways we can manipulate integers.
• ADD
• SUBTRACT
• MULTIPLY
• DIVIDE

3
Adding Integers

• First look at the signs of integers
• Are the signs the same?
• If the signs are the same, we find the sum
• If the signs are different, we find the
  difference.
• 65 -7-4 -155
• 11 -11 -10

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Examples!

• 35
• 8
• 106
• 16
• -5(-7)
• -12
• -134
• -9

• -23(-6)
• -29
• 33(-15)
• 17
• -14(-11)
• -25
• 428
• 50

Always keep the sign of the larger number!
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Subtraction

• When subtracting numbers with different signs,
  change the problem to an addition problem.
• Remember, LEAVE-CHANGE-CHANGE
• 12-48
• -3-6-3-6-9
• 4-124-12-8
• 5-(-5)5510

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Now you try!

• 15-8
• 7
• 23-16
• 7
• -4-5
• -9
• 7-(-9)
• 16

• -16-10
• -26
• 26-(-5)
• 31
• 55-17
• 38
• -32-15
• -47

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Multiplication

• When working with negative integers in
  multiplication , look at how many negative
  numbers you have.
• If there is an even number, the answer will be
  positive
• If there is an odd number, the answer will be
  negative.
• 3(2)(2) 4(-2) 3(-4)(-5) 2(2)(2)(2)
• 12 -8 60 16

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Examples! ?

• 4(-3)
• -12
• 3(2)(6)
• 36
• -6(-8)
• 48
• -2(-3)(-5)
• -30

• -8(-9)(-10)
• -720
• 6(6)
• 36
• -13(3)
• -39
• 6(-4)(-2)
• 48

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Division

• Division is similar to multiplication in that it
  depends on how many negatives are involved.
• If the number of negatives is even, answer is
  positive
• If the number is odd, answer is negative

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Examples! ?

• -8(-2)
• 4
• -164
• -4
• 505
• 10
• 333
• 11

• -72(-9)
• 8
• -16913
• -13
• 486
• 8
• -364
• -9

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Order of Operations

• Remember when we have multiple operations in one
  number sentence to use your order of operations!
• Parenthesis
• Exponents
• Multiplication
• Division
• Addition
• Subtraction

You can remember PEMDAS or Please Excuse My Dear
Aunt Sally
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Lets try a few!

• 3(42-3)(2)
• 3(16-3)(2)
• 313(2)
• 326
• 29
• 32-4(15-4)
• 32-4(11)
• 9-4(11)
• 9-44
• -35

• 162(34)-5
• 162(7)-5
• 8(7)-5
• 56-5
• 51