Properties of Addition

1. Properties of Addition Chapter 2

2. Commutative Property • Order of the numbers does not affect the sum. Examples: 4+2=6 2+4=6

3. Using the Commutative Property Let’s try it … 1) 5+6=11 2)2+10=12 3)3+7=10

4. Identity Property • When zero is added to a number, the sum is the number. Examples: 21+0=21 1,964+0=1,964

5. Variables are … • Symbols used to represent a number or group of numbers. • Letters that take the place of an unknown number. n+4=10 7+n=14

6. Example of a Variable 4) 3+n=6 5) x+2=9 6) 5+4=c

7. Related Number Sentences 7) 2, 4, 6 2+n=6 __________ n+4=6 __________ 6-2=n ___________ 6-n=2 ___________ Come on, challenge me …

8. Challenge Me! • Can you complete the related number sentences? 8) 12, 10, 22 12+n=22 ____________ n+10=22 ____________ 22-12=n _____________ 22-n=10 _____________

9. Keep ‘Em Coming! Find the sum or difference and write the related number sentences. 9) 5+4 = ___________ ____________________ ____________________ ____________________ Throw one my way, I’ll hit it right out of the park!

10. Homerun Coming your Way! Find the sum or difference and write the related number sentences. 10) 26+4=_____________ ___________________ ___________________ ___________________

11. Why Stop Now? – We’re on a Roll! • Let’s write the related number sentences for the problem below. 11) 16, 9, 25 ________________ ________________ ________________ ________________ Let me show you just how bright I am!

12. Brightest Star in the Sky! • Can you figure out the related number sentences for the problem below? 12) 56, 0, 56 ________________ ________________ ________________ ________________

13. Challenge of the Day! Attempt at your own risk!

14. You must have a number sentence to go along with your answer. 13. Sue and Jeff had to clean their entire house for the party. Sue cleaned 7 rooms and Jeff cleaned 5. How many rooms are there in Sue and Jeff’s house? _______________________________

15. Great Job !!!

16. Woops, Try Again!