ADDING, SUBTRACTING, MULTIPLYING AND DIVIDING INTEGERS By :
Katie Kurth and Kateylnn Everhart
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WHAT IS AN INTEGER? Any whole number and 0 Can be positive or
negative A complete unit Negative integer : Any integer that is
less than 0 Positive integer : Any integer greater than 0
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ADDING INTEGERS
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WORDS TO REMEMBER Inverse property of addition: The sum of a
number and its opposite is 0. Example: a + (-a) = 0 -a + a = 0
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ADDING INTEGERS Step 1: start at 0 and move 3 over to the right
Step 2 : begin at 3 and move 1 over to the right Step 3: write the
sum. 3+1=4 since the number landed on was 4 after adding 1 to
3
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ADDING INTEGERS Practice Problems 4+3 3+2 6+1
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ADDING INTEGERS SUMMARY When a number is positive, move that
many units to the right of zero or your starting point.
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SUBTRACTING INTEGERS
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WORDS TO REMEMBER Opposites : Two numbers that are the same
distance from 0 on a number line, but on opposite sides of 0
Subtraction Rule: To subtract an integer, add its opposite 5 8 = 5
+ (-8) = -3 2 (-3) = 2 + 3 = 5
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SUBTRACTING INGETERS Step 1: move 6 units to the right from 0
Step 2: move 2 units away from 6 to the left Step 3: Use the
subtraction rule of adding the opposite to check your answer
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SUBTRACTING INTEGERS Practice Problems 3-1 4-2 7-3
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SUBTRACTING INTEGERS SUMMARY To subtract an integer, add its
opposite.
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MULTIPLYING INTEGERS
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Multiplication is the same as repeated addition 4 x 2 = 2 +2 +
2 + 2 = 8 5(-6) = -6 + (-6) + (-6) + (-6) + (-6) = -30
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MULTIPLYING INTEGERS Find the product by rewriting it as
repeated addition 3 x 15 = 15 + 15 +15 =45 5(-2) = -2 + (-2) + (-2)
+ (-2) + (-2) 3 x 1 = 1 + 1 + 1
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MULTIPLYING INTEGERS Practice problems 3 x 4 -7 x 2 -4 x
(-5)
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MULTIPLYING INTEGERS Things to remember ! The product of a
positive integer and a negative integer is negative 4 x (-4) = -16
The product of two negative integers is positive. -3 x (-3) =
9
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MULTIPLYING INTEGERS SUMMARY The product of two negative
integers is positive. The product of a positive integer and a
negative integer is negative
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DIVIDING INTEGERS
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WORDS TO REMEMBER Quotient: The result of dividing two integers
Related problem: You can rewrite a division problem as the related
multiplication problem. Rules - The rules for multiplication of
integers also hold true for division. The quotient of two integers
with the same sign is positive. The quotient of two integers with
different signs is negative.
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DIVIDING INTEGERS Solve 15 / 3 Step 1: Think? What number times
3 gives you 15 Step 2: Solve using mental math Answer: 5 times 3
gives you 15
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DIVIDING INTEGERS Practice problems 4/2 8/4 9/3
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DIVIDING INTEGERS SUMMARY The quotient of two integers with the
same sign is positive. The quotient of two integers with different
signs is negative. One method for finding the quotient of two
integers is to begin by rewriting the division problem as a
multiplication problem.