1. (Clickers & computer – Online Book)
1.4 Multiplying Integers
(Clickers & computer – Online Book)

2. What is multiplication?
Repeated Addition
For Example…
3 • 2 means to add 3 groups of 2 6
Use the Interactive Math Tool to demonstrate on a number line.

3. Rule #1 for Multiplying Integers
If the signs of two integers are the same (both positive or both negative)
The answer is always positive
For Example…
–2 • (–8) 16

4. Simplify
5 • 8 40
–3 • (–11) 33
Try it!

5. Rule #2 for Multiplying Integers
If the signs of two integers are different
(one positive and one negative)
The answer is always negative
For Example…
–2 • 8 – 16

6. Simplify
5 • (–4)
–20
8 • (–12)
–96
Try it!

7. Simplify
–5 • 6 • (–2)
–30
• (–2) 60
Try it!

8. Simplify
–2 • (–7) • (–5) 10
• (–7)
–70
Try it!

9. Simplify
(–7)2
(–7)•(–7) 49
Try it!

10. Simplify
–82
–(8 • 8)
–64
Try it!

11. Simplify
(–2)4
(–2)•(–2)•(–2)•(–2)
4•(–2)•(–2)
(–8)•(–2) 16
Try it!

12. Simplify
(–3) • 4
(–3)(–3)
+ 12 • 4 + 9 48 57
Try it!

13. Simplify
–62 • 2 + 5
• 2 + 5
–(6 • 6)
• 2 + 5
–36
–72
+ 5
–67
Try it!

14. Evaluate a2 – 2a + 7 for a = –4 (–4)2 – 2(–4) + 7 16 – 2(–4) + 7
16 –
(–8)
16 + 8
+ 7 31
Try it!

15. Evaluate |ab – 5b| for a = –3 and b = 6 |–3 • 6 – 5 • 6| |–18 – 30|+
(–30)|
|–48| 48
Try it!

16. Sample Application Problem
(Please refer to Textbook Example 4 on p.25)

17. Homework
p.26 1,3,7,8-44 even, 47,48,51
(MC #10,11,12)