1. ADDITION
AND SUBTRACTION
OF INTEGERS
The University of Texas at Dallas

2. Introduce symbols
+ (plus)
- (minus)

3. ADDING INTEGERS
We can model integer addition with tiles.
Represent -2 with the fewest number of
tiles
Represent +5 with the fewest number of
tiles.
The University of Texas at Dallas

4. ADDING INTEGERS
What number is represented by combining
the 2 groups of tiles?
Write the number sentence that is
illustrated.
-2 + +5 = +3
The University of Texas at Dallas
+3

5. ADDING INTEGERS
Use your red and yellow tiles to find each sum.
-2 + -3 = ?
The University of Texas at Dallas
ANSWER
+ = -5
-2 + -3 = -5

6. ADDING INTEGERS
The University of Texas at Dallas
-6 + +2 = ?
+ = - 4
+ = +1
-3 + +4 = ?
ANSWER
ANSWER
-6 + +2 = -4
-3 + +4 = +1

7. Addition Rule
1) When the signs are the same,
ADD and keep the sign.
(-2) + (-4) = -6
2) When the signs are different,
SUBTRACT and use the sign of the
bigger number.
(-2) + 4 = 2
2 + (-4) = -2

8. -1 + 3 = ?
1. -4
2. -2
3. 2
4. 4
Answer Now
Negative one plus three is equal to two.

9. -6 + (-3) = ?
1. -9
2. -3
3. 3
4. 9
Answer Now
Negative six plus negative three is equal to
negative nine.

10. Karaoke Time!
Addition Rule: Sung to the tune of
“Row, row, row, your boat”
Same sign, keep and add!
Different sign: subtract,
Take the sign of the bigger number,
Then you will be exact!
Let’s Go

11. When subtracting, change the
subtraction to adding the opposite
(keep-change-change) and then follow
your addition rule.
Example #1: - 4 - (-7)
- 4 + (+7)
Diff. Signs --> Subtract and use larger sign.
3
Example #2: - 3 - 7
- 3 + (-7)
Same Signs --> Add and keep the sign.
-10

12. Which is equivalent to
-12 – (-3)?
Answer Now
1. 15
2. -9
3. -15
4. 9
Negative twelve minus
negative three is equal to
negative nine.

13. 7 – (-2) = ?
Answer Now
1. -9
2. -5
3. 5
4. 9
Seven minus
negative two is equal to nine.