1. Splash Screen

2. Lesson Menu Five-Minute Check (over Lesson 2–6) Main Idea Key Concept: Addition Properties Example 1:Name Addition Properties Example 2:Use Properties to Add Whole Numbers Example 3:Use Properties to Add Decimals Example 4:Partial Sums of 10

3. Main Idea/Vocabulary I will use Associative and Commutative Properties to add whole numbers and decimals mentally.

4. KC 1

5. Example 1 Name Addition Properties Identify the addition property used to rewrite the problem below. 14 + (26 + 5) = (14 + 26) + 5 The grouping of the numbers to be added changes. Answer: This is the Associative Property of Addition.

6. 1.A 2.B 3.C 4.D Example 1 A.Commutative Property B.Associative Property C.Identity Property D.Distributive Property Identify the addition property used to rewrite the problem below. 3 + 5 + 9 = 5 + 3 + 9.

7. Example 2 Use Properties to Add Whole Numbers Aisling counted 21 gray cars, 13 white cars, and 19 red cars. How many cars did she count in all? Since you can easily add 21 and 19, change the order and group those numbers together. 21 + 13 + 19 = 21 + 19 + 13 Commutative Property = (21 + 19) + 13 Associative Property = 40 + 13 Add 21 and 19 mentally. = 53 Add 40 and 13 mentally. Answer: So, Aisling counted 53 cars in all.

8. 1.A 2.B 3.C 4.D Example 2 A.15 movies B.20 movies C.35 movies D.40 movies Louanne saw 12 scary movies, 15 action movies, and 8 comedy movies last year. How many did she see in all?

9. Example 3 Use Properties to Add Decimals Use properties of addition to find 1.7 + 0.6 + 0.3 mentally. Since 1.7 + 0.3 = 2, group 1.7 and 0.3 together. 1.7 + 0.6 + 0.3 = 1.7 + 0.3 + 0.6 Commutative Property = (1.7 + 0.3) + 0.6 Associative Property = 2.0 + 0.6 Add 1.7 and 0.3 mentally. = 2.6 Add 2.0 and 0.6 mentally.

10. 1.A 2.B 3.C 4.D Example 3 A.6.2 B.6.0 C.5.8 D.5.1 Use properties of addition to find 5.1 + 0.2 + 0.9.

11. Example 4 Partial Sums of 10 Use properties of addition to find 24 + 17 mentally. 24 + 17 = (20 + 4) + (10 + 7) 24 = 20 + 4 and 17 = 10 + 7 = 20 + 10 + 4 + 7 Commutative Property = (20 + 10) + (4 + 7) Associative Property = 30 + 11 Add inside the parentheses. = 41 Add 30 and 11 mentally.

12. 1.A 2.B 3.C 4.D Example 4 A.26 B.50 C.60 D.61 Use properties of addition to find 35 + 26.

13. End of the Lesson End Lesson

14. Resources Five-Minute Check (over Lesson 2–6) Image Bank Math Tool Chest Add and Subtract Decimals

15. 1.A 2.B 3.C 4.D Five Minute Check 1 (over Lesson 2–6) A.59.57 B.60 C.58.57 D.58.6 Find 51.37 + 8.2.

16. 1.A 2.B 3.C 4.D Five Minute Check 2 (over Lesson 2–6) A.12.74 B.12.73 C.13.73 D.12.75 Find 18.35 – 5.62.

17. 1.A 2.B 3.C 4.D Five Minute Check 3 (over Lesson 2–6) A.3.92 B.2.019 C.2.919 D.2.28 Find 5.05 – 2.131.

18. 1.A 2.B 3.C 4.D Five Minute Check 4 (over Lesson 2–6) A.7.201 B.7.31 C.7.206 D.7.1 Find 3.19 + 4.016.

19. End of Custom Shows