Adding Integers Lesson

7.NS.1 Apply and extend previous understandings of addition and subtraction to add and subtract rational numbers; represent addition and subtraction on a horizontal or vertical number line diagram.

​Adding Integers

1. Using Integer chips making zero pairs.
2. Using a number line.
3. Using the RULE.

-

-

+

+

+

+

​Three Ways to Add Integers

Adding Rational Numbers

Using counters can help when adding positive & negative numbers. We will use yellow counters to
represent positive numbers and red counters to represent negative numbers

. To use counters

to add positive & negative numbers, use the steps below.

5 + (-7)=

Step 1: Place the number of
positive & negative counters
needed to represent the
problem.

Step 2: Then use the additive
inverse to create zero with as
many counters as possible.

Step 3: Determine what
counters remain. That will be the answer.

Step 1:

5 yellow, positive counters were added.
7 red, negative counters were added.

Step 2:

5 + (-5) = 0 because of the additive inverse.

Step 3:

So only 2 red remain, therefore the answer is -2.

Adding Rational Numbers

Using counters can help when adding positive & negative numbers. We will use yellow counters to
represent positive numbers and red counters to represent negative numbers

.

4 + (-2)=

Step 1: Place the number of
positive & negative counters
needed to represent the
problem.

Step 2: Then use the additive
property to create zero with
as many counters as possible.

Step 3: Determine what
counters remain. That will be
the answer.

Add Integers Using Integer Chips

Write your answer on your Whiteboards and Hold Up

1. -8 + 2 =

2. -9 + (-9) =

3. -2 + 2 =

4. 3 + (-7) =

The answer will be where you end up on the number line.

5 + (-7)= -2

Adding Rational Numbers

When adding positive & negative numbers, positive numbers move us one direction (right or up
depending on the number line) & negative numbers move us in the opposite direction (left or down).

-5

5

5 + (-7)=

-4

-3

-2

-1

0

1

2

3

4

You must start at 0 & move right 5 spaces.

You will then move 7 spaces to the left.

Adding Rational Numbers

When adding positive & negative numbers, positive numbers move us one direction (right or up
depending on the number line) & negative numbers move us in the opposite direction (left or down).

Use the number line to solve the problem below:

-5

5

3 + (-2) =

-4

-3

-2

-1

0

1

2

3

4

Add Integers Using a Number Line

Write your answer on your Whiteboards and Hold Up

1. -7 + 5 =

2. -6 + (-6) =

3. 4 + (-4) =

4. 3 + (-10) =

Rule: Same Signs ADD and Keep the sign in Common.
Easier to use when you have larger Numbers.

2 + 3 = 5 Same Add and Keep the sign they have in common. POSITIVE

-3 + (-9) =-12 Same signs Add and Keep the sign they have in Common. Negative

Rule: Different Signs SUBTRACT and Keep the sign of
the larger absolute value. Easier to use when you have larger Numbers.

(-2) + 3 = 1 Different signs Subtract and Keep the sign of the larger absolute value. Negative.

3 + (-9) =-6 Different signs Subtract and Keep the sign of the larger absolute value. Negative

Add Integers Using the Rule

Write your answer on your Whiteboards and Hold Up

1. -25 + 5 =

2. -12 + (-12) =

3. 44 + (-44) =

4. 15 + (-10) =

​Which Method did you like Best!!

• ​Integer Chips

• Number Line

• Rule

​Write your answer on your Whiteboard!!!