Adding with Negatives

Adding with Integers

how to add numbers when negatives are involved

Number Lines are our Friends!

• As we go to the right on a horizontal number line, the numbers get bigger.

• As we go to the left on a horizontal number line, the numbers get smaller.

• We can use these facts to add and subtract integers on a number line. But first...

Multiple Choice

Any value less than 2 will be to the...

• left of 2

• right of 2

Multiple Choice

Any value greater than -2 will be to the...

• left of -2

• right of -2

Multiple Select

Select all of the numbers that are less than -6.

• 0

• 7

• -7

• -8

• -5

When Adding with Integers...

• If we are adding a positive, we say we are getting "more positive."

• "More Positive" means we are going towards the positive side, or to the right.

• If we are adding a negative, we say we are getting "more negative."

• "More Negative" means we are going towards the negative side, or to the left.

This is in reference to the SECOND number.

The first number is just where you start (more on that later).

Multiple Choice

If I am looking at the expression 2 + 4, am I getting more positive or more negative?

• more positive

• more negative

Multiple Choice

If I am looking at the expression -2 + 4, am I getting more positive or more negative?

• more positive

• more negative

Multiple Choice

If I am looking at the expression 2 + (-4), am I getting more positive or more negative?

• more positive

• more negative

Multiple Choice

If I am looking at the expression -2 + (-4), am I getting more positive or more negative?

• more positive

• more negative

Okay, so how do I add them?

• Step 1: Draw a number line.

• Step 2: Start at the first number.

• Step 3: Determine if you are getting more positive or more negative.

• Step 4: Move the absolute value of the second number in the proper direction, based on step 3.

• Step 5: Your answer is where you land.

Another Example

Multiple Choice

In finding the sum 7 + (-3), I will start at the number...

• 7

• 3

• -7

• -3

Multiple Choice

In finding the sum 7 + (-3), I will be getting...

• more positive

• more negative

Multiple Choice

In finding the sum 7 + (-3), I will be moving...

• 7 spaces to the left

• 7 spaces to the right

• 3 spaces to the left

• 3 spaces to the right

Fill in the Blanks

7 + (-3) = ?

Multiple Choice

In finding the sum -5 + 11, I will start at the number...

• 11

• 5

• -5

• -11

Multiple Choice

In finding the sum -5 + 11, I will be getting...

• more positive

• more negative

Multiple Choice

In finding the sum -5 + 11, I will be moving...

• 11 spaces to the left

• 11 spaces to the right

• 5 spaces to the left

• 5 spaces to the right

Fill in the Blanks

-5 + 11 = ?

Fill in the Blanks

-3 + (-4) = ?

Fill in the Blanks

2 + 3 = ?

Open Ended

Explain, in words, the process for adding integers. Try to write as much as you can remember.

Poll

How do you feel about adding integers?

• I feel great! I totally understand.

• I feel good. I get it for the most part.

• I feel okay. I don't really get it, but I am trying.

• I feel bad. I don't understand this at all.