Transcript Add and Subtract Integers

Chapter 1.5
Adding Integers
A plane descends 1500 ft. Then it descends
another 600 ft. Where is the plane in
relation to where it started?
-1500 + (-600)=
-2100 ft.
Use a number line to find the sum.
1) (-4) + 8 =
-5
0
5
0
5
0
5
2) (-1) + (-3) =
-5
3) 5 + (-7) =
-5
Addition Rule
When the signs are the same, ADD and keep the
sign.
(-2) + (-4) = -6
4 + 6 = 10
When the signs are different, SUBTRACT and use
the sign of the larger number.
(-2) + 4 = 2
2 + (-4) = -2
The OPPOSITE of two numbers add to equal zero.
3 + (-3) = 0
Examples:
-5 + (-66) =
-71
-31 + 68 =
37
-17 + 9 =
-8
80 + 57 =
137
Examples:
5 + (-2) + (-7)=
3 + (-7)
-4
53 + (-32) + (-46)=
21 + (-46)
-25
40 + 33 + 12=
73 + 12
85
Evaluate the expression
X= -22, Y= -12
x + (-5)=
-22 + (-5)
-27
x + 20 + y=
-22 + 20 + (-12)
-2 + (-12)
-14
-19 + y=
-19 + (-12)
-31