1. Add and Subtract Integers
Learning Objective: We will add and subtract positive and negative integers.
What are we going to do today?
What are we going to (skill)?
What are we going to do with (concept)?
Math NS 1.3

2. What do we already know?
Positive integers are on the right side of zero
Negative integers are on the left side of zero
This means that they are opposites = 0
Connect to Learning Objective
Show me a positive number on the white board.
Negative number.
Write two integers that are opposite that equal to zero.
Tell your partner why is the sum of the two integers zero.
Negative
Positive

3. You know how to plot an expression on the number line and find the sum.= 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
RAJ
What is an integer?
Pair share
Pull sticks
Which example is positive integer? Choice A -4
Choice B 9
Tell your partner how do you know which one is a positive integer?
Use a sentence frame 的 knew that _ is a positive integer because_�
Repeat for negative integer. 5

4. You know how to plot an expression on the number line and find the difference.
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. You know how to plot an expression on the number line and find each sum.
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

6. You already learned that subtracting a negative integer gives the same solution as adding its opposite.

7. Vocabulary Define integers: a positive or negative number.
Define a positive integer: whole numbers to the left of zero.
Define a negative integer: whole numbers to the right of zero.
negative
positive

8. Vocabulary Define absolute value: the distance from zero.
Plot each of the integers below on a
number line and then tell the absolute value of each.
(1)
(2)
(5) -1 -5 2

9. You already learned that subtracting a negative integer gives the same solution as adding its opposite. To help predict whether the sum of two integers will be positive or negative, you can use these rules.

10. Is the sum of 2 and 7 positive or negative?
1st Variation
Is the sum of 2 and 7 positive or negative?
Rule: The sum of two positive integers is positive.
2+7=
Solution: The sum of 2 and 7 is positive. 9
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off. 2 7

11. 2nd Variation Is the sum of -2 and -7 positive or negative?
Rule: the sum of two negative integers is negative. =
Solution: The sum of -2 and -7 is negative.
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off. -9 -7 -2

12. 3rd Variation 5 7 -2 Is the sum of -2 and 7 positive or negative?
Rule: the sum of a positive integer and a negative
integer will have the same sign as the integer with
the greater absolute value.
-2 + 7=
Solution: The sum of -2 and 7 is positive.
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off. 5 7 -2

13. Why is this important? If the temperature was 10ｰF at lunch time and
dropped to -5ｰF in the evening. What is the
difference between these temperatures?
= 15 degrees
Mauricio were at the corner store. Mauricio forgot
his money and needs $10 to pay for his treats. If
Omar let Mauricio borrow $10, Mauricio now has
$10.
- $10 + $10 = 0
Does anyone else have any other reason as to why it is important? Which reason is most important to you? Why? You can give me my reason or your reason.

14. Guided Practice - I Do It
Rule: The sum of two positive integers is positive.
1 + 4= 5
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off. 1 4
Solution: The sum of 1 and 4 is positive.

15. Guided Practice - We Do It
Rule: The sum of two positive integers is positive.
5 + 3= 8
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off.
Do I move left or right from 0 for the first integer?
Which way do I move to subtract the second integer? 5 3
Solution: The sum of 5 and 3 is positive.

16. Guided Practice - You Do It
Rule: The sum of two positive integers is positive.
7 + 3= 10
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off. 7 3
Solution: The sum of 7 and 3 is positive.

17. Guided Practice - I Do It
Rule: the sum of two negative integers is negative. = -5
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off. -3 -2
Solution: The sum of -2 and -3 is negative.

18. Guided Practice - We Do It
Rule: the sum of two negative integers is negative. =
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off. -5 -4 -1
Solution: The sum of -1 and -4 is negative.

19. Guided Practice - You Do It
Rule: the sum of two negative integers is negative. =
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off.
-10 -6 -4
Solution: The sum of -6 and- 4 is negative.

20. Guided Practice - I Do It
Rule: the sum of a positive integer and a negative integer will
have the same sign as the integer with the greater absolute
value.
4 - -2=
4 + 2= 6
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off. 4 2
Solution: The difference of 4 and -2 is positive.

21. Guided Practice - We Do It
Rule: the sum of a positive integer and a negative
integer will have the same sign as the integer with
the greater absolute value.
4 - -6=
4 + 6= 10
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off.
Are both sides the same?
What is the sign of the integer with the greatest value? 4 6
Solution: The difference of 4 and -6 is positive.

22. Guided Practice - You Do It
Rule: the sum of a positive integer and a negative
integer will have the same sign as the integer with
the greater absolute value.
3 - -7=
3 + 7 = 10
Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off. 3 7
Solution: The difference of 3 and -7 is positive.

23. Closure Negative Positive What is a whole number to the right of zero?
It is a positive integer.
What is a whole number to the left of zero?
It is a negative integer
What is the distance from zero?
It is the absolute value.
Negative
Positive

24. Share with your partner one thing that you learned today.
Closure
Decide if the sum or difference is positive or negative.
Explain how you decided.
Solve the expression.
= =
Share with your partner one thing that you learned today.

25. Step 1: Change the expression to an addition by using the absolute value.
Step 2: Plot the first integer on the number line.
Step 3: Plot the second integer on the number line beginning where the last number left off.