This document provides instruction on addition strategies for numbers within 20. It begins with defining key addition terms like addends, addition sign, equal sign, and sum. It then covers topics like the cumulative property of addition, counting forward on a 100 square chart and number line, and mentally counting forward. Examples are provided to illustrate changing the order of addends without changing the sum, counting the number of spaces forward from the first addend, and knowing addition number pairs that total 10 (like 5 + 5). Pre- and post-tests assess counting forward on a 100 square chart. Transfer tasks apply the strategies to new addition problems.

1. Addition and
Subtraction Strategies
(within 20)
M1S1U2

2. Hook:
Draw “zero”
number of
apples.

3. Hook:
If you drew any apple,
that is incorrect.
If you did not draw any apples,
that is correct.

4. Applying Past
knowledge to new
situations
Habit of Mind:
(Use what we learned in the past now!)

5. Applying
means to use what we learn.
Habit of Mind:
Past Knowledge
are our past learnings.
New situations
are the things that are happening now.

6. What does it mean to
reason mathematically?
Essential Question:

7. When adding mentally, do
you count forward or
backward?
Topical Essential Question:

8. Pretest:
Instructions: Using the 100 squares, count forward to get to the red number. Start at the blue number.
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100

9. Words of the day
Addition
is a mathematical operation of
putting things and numbers
together and counting them as
one.

10. Words of the day
Addends
are things and numbers that are
put together in addition.

11. Words of the day
Plus
is a word in addition that puts
things and numbers together.

12. Words of the day
Equal
is a word that means
“the same as”.

13. Words of the day
Sum
is the answer in
addition.

14. Topic 1: Parts Of An Addition Number Sentence
- Addends
- Addition Sign
- Equal Sign
- Sum
An addition number sentence has 4 parts:

15. Topic 1: Parts Of An Addition Number Sentence
1 + 3 =
Addends
+
Addition
Sign
Addends
=
Equal Sign Sum

16. Topic 1: Parts Of An Addition Number Sentence
4 + 5 =
Addends
+
Addition
Sign
Addends
=
Equal Sign Sum

17. Topic 1: Parts Of An Addition Number Sentence
6 + 6 =
Addends
+
Addition
Sign
Addends
=
Equal Sign Sum

18. Topic 1: Parts Of An Addition Number Sentence
6 + 6 =
+ =
Label the parts of an addition number sentence.

19. 5 + 4 =
+ =
Topic 1: Parts Of An Addition Number Sentence
Label the parts of an addition number sentence.

20. 3 + 1 =
+ =
Topic 1: Parts Of An Addition Number Sentence
Label the parts of an addition number sentence.

21. Topic 1: Parts Of An Addition Number Sentence
Label the parts of an addition number sentence.

22. Topic 2: Cumulative Property Of Addition
Changing the order of
addends does not
change the sum.

23. Topic 2: Cumulative Property Of Addition
Switching the places of
addends does not
change the answer in
addition.

24. Topic 2: Cumulative Property Of Addition
12 + 6 =
Addends
+
Addition
Sign
Addends
=
Equal Sign Sum
6 + 12 =
Addends
+
Addition
Sign
Addends
=
Equal Sign Sum

25. Topic 2: Cumulative Property Of Addition
14 + 2 =
Addends
+
Addition
Sign
Addends
=
Equal Sign Sum
2 + 14 =
Addends
+
Addition
Sign
Addends
=
Equal Sign Sum

26. Topic 2: Cumulative Property Of Addition
7 + 6 =
Addends
+
Addition
Sign
Addends
=
Equal Sign Sum
6 + 7 =
Addends
+
Addition
Sign
Addends
=
Equal Sign Sum

27. Topic 2: Cumulative Property Of Addition
Change the number of addends and find the sum.
4 + 7 =
+ =
+ =

28. Topic 2: Cumulative Property Of Addition
Change the number of addends and find the sum.
5 + 12 =
+ =
+ =

29. Topic 2: Cumulative Property Of Addition
Change the number of addends and find the sum.
10 + 4 =
+ =
+ =

30. Topic 3: Counting Forward In A 100 Squares
Addition Strategy:
1. Look at the first addend, that is the
starting point.
2. Look at the second addend, that is how
many times you will count forward.
3. The sum is the number you stop at.

31. Topic 3: Counting Forward In A 100 Squares
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
7 + 3 =

32. Topic 3: Counting Forward In A 100 Squares
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
13 + 6 =

33. Topic 3: Counting Forward In A 100 Squares
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
11 + 5 =

34. Topic 3: Counting Forward In A 100 Squares
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
4 + 7 =

35. Topic 3: Counting Forward In A 100 Squares
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
13 + 4 =

36. Topic 3: Counting Forward In A 100 Squares
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
15 + 3 =

37. Topic 4: Counting Forward In A Number Line
Addition Strategy:
1. Look at the first addend, that is the
starting point.
2. Look at the second addend, that is how
many times you will count forward.
3. The sum is the number you stop at.

38. Topic 4: Counting Forward In A Number Line
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
4 + 9 =

39. Topic 4: Counting Forward In A Number Line
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
7 + 5 =

40. Topic 4: Counting Forward In A Number Line
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
9 + 8 =

41. Topic 4: Counting Forward In A Number Line
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
9 + 6 =

42. Topic 4: Counting Forward In A Number Line
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
5 + 7 =

43. Topic 4: Counting Forward In A Number Line
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
5 + 9 =

44. Topic 5: Counting Forward In Mentally
Addition Strategy:
1. Look at the first addend, that is the
starting point.
2. Look at the second addend, that is how
many times you will count forward.
3. The sum is the number you stop at.

45. Topic 5: Counting Forward In Mentally
“Big number in the mind.
Small number in the hand.
Start counting forward.”

46. Topic 5: Counting Forward In Mentally
“Big number in the mind.
Small number in the hand.
Start counting forward.”

47. Topic 5: Counting Forward In Mentally
“___ number in the mind.
____ number in the hand.
Start counting _______.”

48. Topic 5: Counting Forward In Mentally
9 + 5 =
8 + 9 =
5 + 7 =

49. Topic 6: Counting Doubles
Addition Strategy:
Some numbers are paired to make 10. Remember these pairs because they will always make 10.
0 + 10 = 10 10 + 0 = 10
1 + 9 = 10 9 + 1 = 10
2 + 8 = 10 8 + 2 = 10
3 + 7 = 10 7 + 3 = 10
4 + 6 = 10 6 + 4 = 10
5 + 5 = 10 5 + 5 = 10
6 + 4 = 10 4 + 6 = 10
7 + 3 = 10 3 + 7 = 10
8 + 2 = 10 2 + 8 = 10
9 + 1 = 10 1 + 9 = 10

50. Post Test:
Instructions: Using the 100 squares, count forward to get to 20. Start at number 2.
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100

51. 4 + 2 =
+ =
Transfer Task:
Label the parts of an addition number sentence.

52. Transfer Task:
Change the number of addends and find the sum.
4 + 10 =
+ =
+ =

53. Transfer Task:
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
4 + 5 =

54. Transfer Task:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
14 + 5 =

55. Transfer Task:
9 + 5 =
8 + 9 =
5 + 7 =

56. The End.