2. Adding

3. First, you need to know… Associative Property of Addition When: (a + b) + c = a + (b + c) Commutative Property of Addition When: a + b= b + a Zero Property of Addition When: a + 0= a

4. 4,285 + 124 Always start with the ones.

5. Let’s Try Some! 4,285 + 124 4,409 2,402 +1,789 4,191 1 11

6. More Practice! 1,891 + 298 2,189 5,765 + 6,341 12,106 11 11

7. Subtraction

8. 4,987 - 2,158 Always start with the ones.

9. Let’s Try Some! 4,987 - 2,158 3,230 - 320 177 212 2,829 1,910

10. More Practice! 5,290 - 1,488 9,222 - 6,180 412810 112 3,802 3,042