Chapter One
Adding & Subtracting Integers
Adding Integers Key Concepts

Adding Integers with Same Sign

The sum of two positive integers is positive.


3+2=5
The sum of two negative integers is negative.


-3+(-2) = -5
Adding Integers with Different Signs

To add two different signs, find the difference of their absolute values.
The result will keep the sign of the integer with the greater absolute
value.
 3+(−2)
 Find the difference of their absolute values |3| − |-2| = 3 − 2 =1
 The result will keep the sign of the highest absolute value
 |3| > | - 2| therefore the result will be positive 1
 3+ (-2) = 1
Find the sums:
14 + (-11)
1.

3
-6 + (-7)
2.

-13
-26 + (-39)
3.

-65
450 + (-350)
4.

100
19 + (-9) + 45 + (-32)
5.

23
Geography
The highest peak at Mt. Ellsworth in Montana is 3,275 m
lower than the highest peak of Mt. Kilimanjaro in Kenya,
at 5,895 m. Find the elevation of the highest peak at Mt.
Ellsworth.
1. First find the expression.
2. Then evaluate the expression to find the final answer.

1.
5,895 − 3,275
2.
2,620 meters
Subtracting Integers Key Concepts

Subtracting Integers

To subtract an Integer, add its opposite.
 4 − 7 = (in words: positive four minus positive seven)
 4 + (−7) adding the opposite of positive seven
 Use the rule of adding integers with different signs:
Find the difference of the absolute values
 |-7| − |4| = 7 − 4 = 3
 The result will keep the sign of the highest absolute value
 |-7| > |4| therefore the result will be negative
 4 + (−7) = -3

4
− 7 = -3
Write each difference as a sum and solve
6-2
1.

6 + (-2) = 4
6 – (-2)
2.

6+2=8
-6 – 2
3.

-6 + (-2) = -8
2–6
4.

2 + (-6) = -4
35 – 15
5.

35 + (-15) = 20
Account Balances



Terry has $43 in a checking account. If Terry writes a
check for $62, what is the new account balance?
First write an expression
Solve the expression to find the result


$43 – $62
43 + (-62) = -$19