3. What You Will Learn
Some definitions related to integers.
4. What You Will Learn
Some definitions related to integers.
Rules for adding and subtracting
integers.
5. What You Will Learn
Some definitions related to integers.
Rules for adding and subtracting
integers.
A method for proving that a rule is true.
6. What You Will Learn
Some definitions related to integers.
Rules for adding and subtracting
integers.
A method for proving that a rule is true.
Are you ready??
37. Negative Numbers Are Used to
Show Debt
Let’s say your parents bought a car but
had to get a loan from the bank for $5,000.
When counting all their money they add
in -$5.000 to show they still owe the bank.
43. Integer Addition Rules
Rule #1 – If the signs are the same,
pretend the signs aren’t there. Add
the numbers and then put the sign of
the addends in front of your answer.
44. Integer Addition Rules
Rule #1 – If the signs are the same,
pretend the signs aren’t there. Add
the numbers and then put the sign of
the addends in front of your answer.
9 + 5 = 14
45. Integer Addition Rules
Rule #1 – If the signs are the same,
pretend the signs aren’t there. Add
the numbers and then put the sign of
the addends in front of your answer.
9 + 5 = 14
-9 + -5 = -14
56. Integer Addition Rules
Rule #2 – If the signs are different
pretend the signs aren’t there.
Subtract the smaller from the larger
one and put the sign of the one with
the larger absolute value in front of
your answer.
57. Integer Addition Rules
Rule #2 – If the signs are different
pretend the signs aren’t there.
Subtract the smaller from the larger
one and put the sign of the one with
the larger absolute value in front of
your answer.
-9 + +5 =
58. Integer Addition Rules
Rule #2 – If the signs are different
pretend the signs aren’t there.
Subtract the smaller from the larger
one and put the sign of the one with
the larger absolute value in front of
your answer.
-9 + +5 =
9-5=4
59. Integer Addition Rules
Rule #2 – If the signs are different
pretend the signs aren’t there.
Subtract the smaller from the larger
one and put the sign of the one with
the larger absolute value in front of
your answer.
Larger abs. value -9 + +5 =
9-5=4
60. Integer Addition Rules
Rule #2 – If the signs are different
pretend the signs aren’t there.
Subtract the smaller from the larger
one and put the sign of the one with
the larger absolute value in front of
your answer.
Larger abs. value -9 + +5 =
9-5=4
61. Integer Addition Rules
Rule #2 – If the signs are different
pretend the signs aren’t there.
Subtract the smaller from the larger
one and put the sign of the one with
the larger absolute value in front of
your answer.
-9 + +5 =
Larger abs. value
9 - 5 = 4 Answer = - 4
83. One Way to Add Integers Is
With a Number Line
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
84. One Way to Add Integers Is
With a Number Line
When the number is positive, count
to the right.
When the number is negative, count
to the left.
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
85. One Way to Add Integers Is
With a Number Line
When the number is positive, count
to the right.
When the number is negative, count
to the left.
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
86. One Way to Add Integers Is
With a Number Line
When the number is positive, count
to the right.
When the number is negative, count
to the left.
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
87. One Way to Add Integers Is
With a Number Line
When the number is positive, count
to the right.
When the number is negative, count
to the left.
- +
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
88. One Way to Add Integers Is
With a Number Line
When the number is positive, count
to the right.
When the number is negative, count
to the left.
- +
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
89. One Way to Add Integers Is
With a Number Line
+3 + -5 =
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
90. One Way to Add Integers Is
With a Number Line
+3 + -5 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
91. One Way to Add Integers Is
With a Number Line
+3 + -5 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
92. One Way to Add Integers Is
With a Number Line
+3 + -5 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
93. One Way to Add Integers Is
With a Number Line
+3 + -5 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
94. One Way to Add Integers Is
With a Number Line
+3 + -5 = -2
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
95. One Way to Add Integers Is
With a Number Line
+6 + -4 =
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
96. One Way to Add Integers Is
With a Number Line
+6 + -4 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
97. One Way to Add Integers Is
With a Number Line
+6 + -4 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
98. One Way to Add Integers Is
With a Number Line
+6 + -4 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
99. One Way to Add Integers Is
With a Number Line
+6 + -4 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
100. One Way to Add Integers Is
With a Number Line
+6 + -4 = +2
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
101. One Way to Add Integers Is
With a Number Line
+3 + -7 =
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
102. One Way to Add Integers Is
With a Number Line
+3 + -7 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
103. One Way to Add Integers Is
With a Number Line
+3 + -7 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
104. One Way to Add Integers Is
With a Number Line
+3 + -7 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
105. One Way to Add Integers Is
With a Number Line
+3 + -7 =
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
106. One Way to Add Integers Is
With a Number Line
+3 + -7 = -4
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
107. One Way to Add Integers Is
With a Number Line
-3 + +7 =
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
108. One Way to Add Integers Is
With a Number Line
-3 + +7 =
-
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
109. One Way to Add Integers Is
With a Number Line
-3 + +7 =
-
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
110. One Way to Add Integers Is
With a Number Line
-3 + +7 =
-
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
+
111. One Way to Add Integers Is
With a Number Line
-3 + +7 =
-
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
+
112. One Way to Add Integers Is
With a Number Line
-3 + +7 = +4
-
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
+
116. Integer Subtraction Rule
Subtracting a negative number is the
same as adding a positive. Change
the signs and add.
2 – (-7)
is the same as
2 + (+7)
117. Integer Subtraction Rule
Subtracting a negative number is the
same as adding a positive. Change
the signs and add.
2 – (-7)
is the same as
2 + (+7)
2 + 7 = 9!
127. How do we know that
“Subtracting a negative number
is the same as adding a positive”
is true?
128. How do we know that
“Subtracting a negative number
is the same as adding a positive”
is true?
We can use the same
method we use to check our
answers when we subtract.
173. Integer Addition Rules
Rule #1 – If the signs are the same,
pretend the signs aren’t there. Add
the numbers and then put the sign of
the addends in front of your answer.
174. Integer Addition Rules
Rule #1 – If the signs are the same,
pretend the signs aren’t there. Add
the numbers and then put the sign of
the addends in front of your answer.
9 + 5 = 14
175. Integer Addition Rules
Rule #1 – If the signs are the same,
pretend the signs aren’t there. Add
the numbers and then put the sign of
the addends in front of your answer.
9 + 5 = 14
-9 + -5 = -14
177. Integer Addition Rules
Rule #2 – If the signs are different pretend
the signs aren’t there. Subtract the smaller
from the larger one and put the sign of the
one with the larger absolute value in front
of your answer.
178. Integer Addition Rules
Rule #2 – If the signs are different pretend
the signs aren’t there. Subtract the smaller
from the larger one and put the sign of the
one with the larger absolute value in front
of your answer.
-9 + +5 =
179. Integer Addition Rules
Rule #2 – If the signs are different pretend
the signs aren’t there. Subtract the smaller
from the larger one and put the sign of the
one with the larger absolute value in front
of your answer.
-9 + +5 =
9-5=4
180. Integer Addition Rules
Rule #2 – If the signs are different pretend
the signs aren’t there. Subtract the smaller
from the larger one and put the sign of the
one with the larger absolute value in front
of your answer.
Larger abs. value -9 + +5 =
9-5=4
181. Integer Addition Rules
Rule #2 – If the signs are different pretend
the signs aren’t there. Subtract the smaller
from the larger one and put the sign of the
one with the larger absolute value in front
of your answer.
Larger abs. value -9 + +5 =
9-5=4
182. Integer Addition Rules
Rule #2 – If the signs are different pretend
the signs aren’t there. Subtract the smaller
from the larger one and put the sign of the
one with the larger absolute value in front
of your answer.
-9 + +5 =
Larger abs. value
9 - 5 = 4 Answer = - 4
183. One Way to Add Integers Is
With a Number Line
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
184. One Way to Add Integers Is
With a Number Line
When the number is positive, count
to the right.
When the number is negative, count
to the left.
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
185. One Way to Add Integers Is
With a Number Line
When the number is positive, count
to the right.
When the number is negative, count
to the left.
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
186. One Way to Add Integers Is
With a Number Line
When the number is positive, count
to the right.
When the number is negative, count
to the left.
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
187. One Way to Add Integers Is
With a Number Line
When the number is positive, count
to the right.
When the number is negative, count
to the left.
- +
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
188. One Way to Add Integers Is
With a Number Line
When the number is positive, count
to the right.
When the number is negative, count
to the left.
- +
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
192. Integer Subtraction Rule
Subtracting a negative number is the
same as adding a positive. Change
the signs and add.
2 – (-7)
is the same as
2 + (+7)
193. Integer Subtraction Rule
Subtracting a negative number is the
same as adding a positive. Change
the signs and add.
2 – (-7)
is the same as
2 + (+7)
2 + 7 = 9!
194. How do we know that
“Subtracting a negative number
is the same as adding a positive”
is true?
195. How do we know that
“Subtracting a negative number
is the same as adding a positive”
is true?
We can use the same
method we use to check our
answers when we subtract.