1. Lesson Presentation
Lesson Quizzes 1

2. Sunshine State Standards
Preview of MA.7.A.3.1 Use and justify the rules for…subtracting…integers.
Preview of MA.7.A.3.2 Subtract…integers,…including solving problems in everyday contexts.

3. Subtracting Integers on a Number Line
Move left on a number line to subtract a positive integer.
Move right on a number line to subtract a negative integer.
Confused???
Subtracting Integers on a Number Line 3

4. Slash & Dash
When subtracting a positive number – use “SLASH & DASH” -4 – 3 = Keep the -4 SLASH the subtraction symbol (+) Mark a DASH on the 3 to make it negative = -7

5. Slash & Slash
When subtracting a negative number – use “SLASH & SLASH” -4 – -3 = Keep the -4 SLASH the subtraction symbol (+) SLASH the -3 to make it a positive = -1

6. Keep, Change, Change KEEP, CHANGE, CHANGE
Some teachers teach Slash/Slash or Slash/Dash as
KEEP, CHANGE, CHANGE

7. Additional Example 1: Writing Integer Subtraction
Write the subtraction modeled on each number line. A. B. –4 –3
–8 –7 – 6 –5 –4 –3 –2 –
The subtraction modeled is –3 – 4 = –7.
– (–9)
(–5)
–6 –5 –4 –3 –2 –
The subtraction modeled is –5 – (–9) = 4. 7

8. Write the subtraction modeled on each number line.
Check It Out: Example 1
Write the subtraction modeled on each number line. A. B. –5 –2
–8 –7 – 6 –5 –4 –3 –2 –
The subtraction modeled is –5 – 2 = –7.
–(–5)
(–3)
–6 –5 –4 –3 –2 –
The subtraction modeled is –3 – (–5) = 2. 8

9. Additional Example 2A: Subtracting Integers
Find the difference.
4 – 6
(–6) 4
–3 –2 –
4 – 6 = –2 9

10. Additional Example 2B: Subtracting Integers
Find the difference.
3 – (–3) 3
–(–3) –
3 – (–3) = 6 10

11. Check It Out: Example 2A Find the difference. 2 – (–5) 2 – (–5)–
2 – (–5) = 7 11

12. Check It Out: Example 2B Find the difference. 3 – 6 (–6) 3
–3 –2 –
3 – 6 = –3 12

13. Additional Example 3: Evaluating Integer Expressions
Evaluate a – 4 for a = 2.
a – 4
Write the expression.
2 – 4
Substitute 2 for a. –2
Subtract. 13

14. Check It Out: Example 3 Evaluate b – 6 for b= 8. b – 6
Write the expression.
8 – 6
Substitute 8 for b. 2
Subtract. 14

15. Lesson Quiz
Standard Lesson Quiz 15

16. Evaluate x – (–7) for each value of x. 3. x = –2 4. x = 5
Lesson Quiz
Find each difference.
1. 8 – –9 – (–3)
Evaluate x – (–7) for each value of x.
3. x = – x = 5
5. The peak of Mt. Everest is approximately 26,544 ft above sea level. The shore of the Dead Sea is about 1,200 ft below sea level. How much higher is the peak of Mt. Everest than the shore of the Dead Sea? 3 –6 5 12
27,744 ft 16

17. Lesson Quiz
1. Find the difference. 9 – 6
A. 3
B. –3
C. 15
D. –15 17

18. 2. Find the difference. –11 – (–8) A. 3 B. –3 C. 19 D. –19
Lesson Quiz
2. Find the difference. –11 – (–8)
A. 3
B. –3
C. 19
D. –19 18

19. Lesson Quiz 3. Evaluate p – (–8) for p = –9. A. 17 B. 1 C. –1 D. –1719

20. Lesson Quiz 4. Evaluate s – (–8) for s = 13. A. 21 B. 5 C. –5 D. –2120

21. Lesson Quiz
5. A submarine is 150 feet below the sea level. An airplane is 1,000 feet above the sea level and directly above the submarine. What is the distance between the airplane and the submarine?
A. 850 ft
B. 1,000 ft
C. 1,150 ft
D. 1,500 ft 21