1. Warm Up: Thursday September 3
What do you notice about these problems?
9 x 4 = 36
-9 x 4 = -36
9 x -4 = -36
-9 x -4 = 36

2. Warm Up: Thursday September 3*
-1 ½ + 3 =
(- 5.30) =
.25 – (- 1.45) =

3. Multiplying and Dividing Integers
September 3, 2015

4. Rules When multiplying and dividing integers there are TWO rules:
When multiplying or dividing integers that have the SAME sign, the answer is POSITIVE.
Positive x positive = positive
Negative x negative = positive
+7 x +12 = +84
-6 x –5 = +30

5. Rules continued… Rule 2: Positive x negative = negative
When multiplying or dividing integers whose signs are DIFFERENT, the answer will always be NEGATIVE.
Positive x negative = negative
Negative x positive = negative
+8 x –4 = -32
-5 x +7 = -35

6. Let’s Play TIC TAC TOE

7. Let’s Practice!
What sign would the answer have in front of the integer???
-5 x -7 = ???

8. POSITIVE!!!

9. What sign will be in front of the answer??
How about…
-6 x 9 = ???
What sign will be in front of the answer??

10. NEGATIVE!!!

11. Try this one!
What sign will be in front of the answer???
-81 ÷ 9 = ???

12. NEGATIVE!!!

13. Let’s solve some problems!
-8 x –9 =

14. 72

15. 4 x 12 =

16. 48

17. -45 ÷ 5 =

18. -9

19. -63 ÷ 7 =

20. -9

21. -8 x –11 =

22. 88

23. Remember… When multiplying and dividing integers:
Same signs = a positive
Different signs = a negative

24. Let’s Try fractions and Decimals
2.5 x -4.1

26. (-3)(-3)(-3)

27. (-9.50) x 3