
A number that is greater than zero

A number that is less than zero.

Numbers that are the same distance
from zero in the opposite direction.

All whole numbers and their opposites on
a number line
9 opposite -9
negative
positive
Is like driving in traffic. You have to watch
for the signs!

If you don’t see a sign in front of a
number, don’t panic! No sign means it is
a positive number!

Positive integers are on the right side of zero.
4

Negative integers are on the left side of zero.
-4

This means that they are opposites.
Negative
Positive
-3 + 3 = 0
Comparing Integers
Use the number line to compare the
following integers with >, <, or =.
1
<
<
-2
-3
-5
>
-4
0
Hint: On a number line, the number to the left is
always less than the number to the right.
Comparing Integers
Use the number line to compare
the following integers with >, <,
or =.
>
-5
-5
>
-3
0
0
>
-1
Hint: On a number line, the number on
the top is always greater than the number
on the bottom.
Ordering Integers
Use the number line to put the
following integers in order from least
to
-4, 3,greatest.
0, and -5
-5, -4, 0, 3
Now, you’re probably saying,
“That’s interesting and
everything, BUT where are
negative numbers in the real
world??
??
30
20
10
0
-10
-20
-30
-40
-50
Positive and negative numbers
are used when keeping track of
money.
+ Positive +
$$ you earn
- Negative $$ you spend
3 or +3

Gain 3 pounds:

Withdraw $15:

5 feet below sea level:

Move ahead 4 spaces:
-15
-5
4 or +4
If your mom loaned you $10 for pizza,
Mom,
I. O. U.
$10
The $10 you owe her is described by
the integer -10.
You know how to plot an expression on the number line and find
the sum.
5 + -2 =
3
Step 1: Plot the first integer on the
number line.
Step 2: Plot the second integer on
the number line beginning where
the last number left off.
-2
5
5 + -2=
3
Step 1: Plot the first integer on the
number line.
Step 2: Plot the second integer on
the number line beginning where
the last number left off.
-2
5
-3 + -1 =
Step 1: Plot the first integer on the
number line.
Step 2: Plot the second integer on
the number line beginning where
the last number left off.
-4
-1
-3
Rule #1 – If
 (+) + (+) = (+)
 (-) + (-) = (-)
the signs are
the SAME,
 EXAMPLE:
ADD the
5+1=6
numbers and
then KEEP the
sign of the
-2 + -5 = -7
addends.

Rule #2 – If the signs of
the addends are
DIFFERENT,
SUBTRACT and keep
the SIGN of the larger
number
 EXAMPLE:
-5 + 3 = -2
+ -5 = -8
10
4 + 6 =
 +3 + (+4) =7
 -6 + -7 = -13
14
5 + 9 =
 -9 + -9 = -18
 -3
Adding Integers Using a Number Line
* adding a positive integer *
ex. (-6) + 5 = -1
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
+
then count forward or right 5 spaces
Solve the Problems
• 8+6=
14
• (-9) + 5 = -4
• (–11) + 11 = 0
• (–8) + 16 = 8
Integer Subtraction Rule
Subtracting a negative number
is the same as adding a
positive. Change the signs and
add.
CHANGE
CHANGE
KEEP
ex. -1 – (-2) is the same as
-1 + (+2) and -1 + 2 = 1