1. Properties: Addition and Subtraction Day 2

2. Review: Properties of Addition
Match each property to its definition.
Zero Property Of Addition ____________
Commutative Property Of Addition __________
Associative Property Of Addition ___________
Definitions:
A.) When you change the way addends are grouped, the sum stays the same.
B.) When you change the order of the addends, the sum stays the same.
C.) When you add zero to a number, the sum is that number.
C Example: 0+16=16
B Example: = 7 + 3
A Example: (6+9)+4= 6+(9+4)

3. Now that you know the three rules of addition, there is one more rule to learn . . .

4. Rule of Subtraction: Zeros in Subtraction
1.) When you subtract zero from a number, the difference is that number.
7-0=7
2.) When you subtract a number from itself, the difference is 0.
7-7=0

5. Practice Which of these problems use the Zeros in Subtraction rule?
B.) = 133 D.) 1, = 1,211

6. Practice
Complete problems #1-20 on page 61 in your math book.