Modeling Integer Addition

Modeling Integer Addition

Using tiles and number lines

Tiles

• Positive Numbers are represented by yellow tiles.

• Negative Numbers are represented by red tiles.

• A red tile and a yellow tile cancel each other out to form a zero pair.

Multiple Choice

Which mathematical expression is represented by these tiles?

• -5 + 2

• 5 + (-2)

• 5 + 2

• (-5) + (-2)

Multiple Choice

Which mathematical expression is represented by these tiles?

• 8 + (-9)

• 8 + 9

• (-8) + 9

• (-8) + (-9)

Zero Pairs

When you have zero pairs, they cancel each other out. Once you have crossed out all of the pairs, you are left with your answer.

Fill in the Blank

Use the tiles to help you determine the answer to 5 + (-2)

Fill in the Blank

Use the tiles to help you determine the answer to 8 + (-9)

What if all of the counters are the same color?

If there are no zero pairs to cross out then you just add what you have.

If you don't have counters, you can draw + and - symbols.

Use this strategy to help you solve the following questions.

Multiple Choice

5 + (-1) =

• 4

• 6

• -4

• 5

Multiple Choice

(-2) + (-6) =

• 8

• 4

• -8

• -4

Multiple Choice

(-7) + 5

• 2

• 12

• -12

• -2

Multiple Choice

(-3) + 6

• 9

• 3

• -3

• -9

Multiple Choice

4 + (-9)

• 13

• -13

• 5

• -5

Number Line

• Start at zero.

• Move to the first number.

• Follow the directions of the second number.

• Where you land is the answer.

Draw a number line labelled -10 to +10

to help you solve the following expressions.

Fill in the Blank

6 + -2

Fill in the Blank

(-3) + 5

Fill in the Blank

(-3) + (-2)

Fill in the Blank

4 + (-6) =

Rules

• If the signs are the same, add

• If the signs are different, subtract and keep the sign of the heavier number.

Multiple Choice

13 + (-2) =

• 15

• -15

• 11

• -11

Multiple Choice

(-2) + 7 =

• 9

• -9

• 5

• -5

Fill in the Blank

15 + (-5)

Fill in the Blank

(-15) + (-5)

Fill in the Blank

(-15) + (5)

Fill in the Blank

15 + 5 =

Fill in the Blank

15 + 5 =