1. Properties and Numbers 1.4

2. Deductive Reasoning Using facts, properties or rules to reach a valid conclusion Conjecture: statement that could be true of false Counter Example: an example that shows a statement is not true.

3. Ex: State whether each conjecture is true. If not give a counterexample. The sum of an even and an odd number is always even. False: 4+1 =5 which is odd

4. Commutative Properties: Change Order Addition Rule: Ex: Multiplication Rule: Ex:

5. Associative Properties: Change Grouping Addition (a+b)+c =a+(b+c) Ex: Multiplication Ex:

6. Identity Properties Addition (0) Rule: a + 0 = a Ex: 7 + 0 = 7 Multiplication(1) Rule: Ex:

7. Name the Property Example: 4+(a+3)=(a+3) +4 Answer: Commutative because the numbers changed order Example: 1(3c)=3c Answer: Identity Property because you multiplied by 1 and the number did not change

8. Name the Property Ex: 14+(9+10)=(14+9)+10 Answer: Associative because the grouping symbols changed Ex: d+0 =d Answer: Identity of addition because you added by 0 and the result stayed the same

9. Simplify the phrase using the properties Ex: 9 +(5+y)

10. Answer the following 2 questions: 1.) Is division of whole numbers associative? If not give a counterexample 2.) Is subtraction of whole numbers commutative? If not give a counterexample

11. Homework Page 22 (14-39 all, 42-48 even)