1. Section 3.5 Multiplying and Dividing Integers

2. Mult./Dividing Integer Rules  1. When you mult./or divide 2 integers with the same sign, the product (the answer) is positive.  Example: 2 x 5= 10 same sign  -2 x -5 = 10 same sign

3. Your turn  -3 x -3= _____ same sign?  2 x 2 = ______ same or diff signs?  -6 x -1 = _____  -5 x -2 = _____

4. Rule # 2  When you mult. Or divide 2 integers with different signs, the product will be negative.  Example: -2 x 3 = ______  -1 x 4 = ______  10 divided by -5 = ______

5. Your turn  Hint first determine sign:  1. -4 x 2 = ___________  -12 divided by 6 = ______  36 divided by -6= ______  12 x 2= ______  -1 x -5= _____  -15 divided by -3 = _____

6. Complete each number sentence. Then write 2 example to illustrate each relationship.  Positive * positive = ___________  Ex: ______________  _________________

7. Look at worksheet 3.5  Problem # 1.  Positive divided by positive = ?  __________  Two examples: _____________ ________________________________________

8. Look at problem # 9  Circle the word ESTIMATE in the directions.  -72 x 57 ( Hint first round to the tens place, then times)  -72 becomes ____  57 becomes _____

9. Problem # 9  -70 x 60= ?

10. Problem # 11  Example of estimating when dividing; remember make them easy to do in your head!  -476 divided by 90  (first is the answer going to be – or +???)  Does 9 go into 476 even? If not what can we change 476 to so it does?

11. # 11  -476 divided by 90  9 x3= 27; 9x4=35;9x5=45; 9x6=54  So 9x what is the closest?

12. #11  -476 divided by 90  9 x 5 = 45  So change the -476 to -450 and divide by 90.  Answer:

13. Use order of operations  PEMDAS  Example: (4 x 6)divided by (-3)= ?  what do you do first?  24/-3 = ____

14. Lets do a few together  # 17. -36 / 9 + 4(-7)  # 18. -52 / (-4) + (-3)(-6)

15. A few more together  #19. -13 + (-5)(-4)  20. -8(9) – 4(-7)

16. What you learned today  When mult or dividing:  Same signs answer is positive  Different signs answer is negative  Be REALLY careful when doing order of operations!!! PEMDAS

17. Assignment:  Worksheet 3-5 all  Work with partner!