1. Preview
Warm Up
California Standards
Lesson Presentation

2. Warm Up
Add.
1. – –3 + (–4)
(–5) (–4)
5. –6 + (–1) 6. –6 + 1 4 –7 2 –1 –7 –5

3. Number Sense (NS2.3) - Solve addition, subtraction, multiplication, and division problems, including those arising in concrete situations, that use positive and negative integers and combinations of these operations.
Also covered: AF1.2
California Standards

4. Objective: You will learn how to subtract integers.

5. Just Remember…
When subtracting Integers…

6. Example 1: Modeling Integer Subtraction
Find the difference.
4 – 1
Team +
Team -

7. Example 2: Modeling Integer Subtraction
Find the difference.
–3 – 1
Team +
Team -

8. Example 3: Modeling Integer Subtraction
Find the difference.
–2 – (–4)
Team +
Team -

9. Team + Team - Check It Out! Example 4
Use a number line to find the difference.
3 – 2
Team +
Team -

10. Team + Team - Check It Out! Example 5
Use a number line to find the difference.
–2 – 4
Team +
Team -

11. Team + Team - Check It Out! Example 6
Use a number line to find the difference.
–4 – (–2)
Team +
Team -

12. You can also subtract an integer by adding its opposite
You can also subtract an integer by adding its opposite. You can then use the rules for addition of integers.

13. Example 7: Subtracting Integers by Adding the Opposite
Find each difference.
A. 5 – (–2)
B. –3 – 7
C. – 1 – (–8)

14. Check It Out! Example 8
Find each difference.
A. 4 – 2
B. –2 – (–6)
C. –1 – 4

15. Evaluate x – y for each set of values.
Example 9: Evaluating Expressions with Integers
Evaluate x – y for each set of values.
A. x = –3 and y = 2
B. x = 4 and y = –6

16. Evaluate x – y for each set of values.
Check It Out! Example 10
Evaluate x – y for each set of values.
A. x = –4 and y = –3
B. x = –4 and y = 5

17. Example 11: Temperature Application
Find the difference between 32°F and –10°F.
The difference in temperature is 42°F.

18. Find the difference between 8°F and –5°F.
Check It Out! Example 12
Find the difference between 8°F and –5°F.
The difference in temperature is 13°F.

19. Home Learning
On-Line Tutoring
Walkin’ The Plank!

20. Lesson Quiz
Use a number line to find the difference.
1. 3 – 9
Find each difference.
2. –7 – –3 – (–5)
4. Evaluate x – y + z for x = –4, y = 5, and z = –10. –6
–11 2
–19
5. On January 1, 2002, the high temperature was 81F in Kona, Hawaii. The low temperature was –29F in Barrow, Alaska. What was the difference between the two temperatures?
110F