2.OA.2

Fluently add and subtract within 20 using mental strategies.2 By end of Grade 2, know from memory all sums of two one-digit numbers.

1. Add these 3 numbers: 3+4+3
2. Add these 3 numbers: 2+4+1
3. Add these 3 numbers: 3+2+1
4. Add these 3 numbers: 7+1+1
5. Add these 3 numbers: 1+1+2
6. Add these 3 numbers: 5+2+1
7. Number Detectives ? + 3 = 6
8. Word Wise: 5 more than 4
9. Word Wise: 5 more than 8
10. Add these 3 numbers: 8 + 3 + 2
11. Add these 3 numbers: 9 + 1 + 6
12. Add these 3 numbers: 4 + 4 + 3
13. Word Wise: The total of 8 and 11
14. Word Wise: The sum of 14 and 3
15. Word Wise: 12 more than 5
16. Word Wise: 6 add 14
17. Word Wise: 11 plus 9
18. Same or different? Click all boxes with answer 18
19. Same or Different? Click all boxes with answer 16
20. Number detectives: Mysteries of 15
21. Number detectives: Mysteries of 16
22. Number detectives: Mysteries of 13
23. Number detectives: Mysteries of 17
24. Number detectives: Mysteries of 14
25. N/D Mysteries of 20! 17+, 11+, 15+
26. N/D Mysteries of 20! 7+, 10+, 8+
27. N/D Mysteries of 20! 6+, 9+, 3+
28. N/D Mysteries of 20! 20+, 5+, 2+
29. Use the Pattern: 4 + 9, + 10, + 11
30. Use the Pattern: 5 + 9, + 10, + 11
31. Use the Pattern: 6 + 9, + 10, + 11
32. Use the Pattern: 7 + 9, + 10, + 11
33. Use the Pattern: 8 + 9, + 10, + 11
34. Addition Chains: 3 + 2 + 4 + 2, 7 + 2 + 3 + 4
35. Subtraction chain 8 - 4 = 4, 4 - 2 = ?
36. Subtraction chain 7 - 2 = 5, 5 - 2 = ?
37. Subtraction chain 9 - 3 = 6, 6 - 2 = ?
38. Subtraction chain 6 - 3 = 3, 3 - 1 = ?
39. Subtraction chain 8 - 2 = 6, 6 - 1 = ?
40. Subtraction chain 9 - 1 = 8, 8 - 2 = ?
41. Subtraction chain 8 - 3 = 5, 5 - 2 = ?
42. Subtraction chain 6 - 2 = 4, 4 - 2 = ?
43. Subtraction chain 7 - 3 = 4, 4 - 1 = ?
44. Subtraction chain 9 - 2 = 7, 7 - 3 = ?
45. Number detectives: ? - 6 = 3
46. Number detectives: ? - 7 = 2
47. Number detectives: 14 - 6 = ?
48. Number detectives: 15 - 9 = ?
49. Number detectives: 11 - 8 = ?
50. Number detectives: 13 - 5 = ?
51. Number detectives: 15 - 13 = ?
52. Number detectives: 14 - ? = 4
53. Number detectives: 11 - ? = 5
54. Number detectives: 10 - ? = 8
55. Number detectives: 13 - ? = 5
56. Number detectives: 14 - ? = 7
57. Word Wise: Subtract 14 from 20
58. Word Wise: 20 take away 11
59. Word Wise: 14 take away 6
60. Word Wise: 11 less than 19
61. Word Wise: 13 less than 20
62. Word Wise: 11 less than 16
63. Subtraction chain 20 - 12 = ? - 6 = 2
64. Word Wise!: Subtract 13 from 20
65. Word Wise!: Subtract 15 from 20
66. Word Wise!: Subtract 8 from 20
67. Word Wise!: Subtract 11 from 20
68. Word Wise!: Subtract 17 from 20
69. Word Wise!: Subtract 5 from 20
70. Word Wise!: 12 minus 7
71. Word Wise!: 20 take away 4
72. Word Wise!: 20 take away 7
73. Word Wise!: 19 less than 19
74. Word Wise!: 3 less than 20
75. Word Wise!: 10 less than 20
76. Subtract 8 (from 16, 15, 12)
77. Subtract 6 (from 12, 11, 13)
78. Subtract 5 (from 14, 11, 8)
79. Subtract 7 (from 14, 16, 11)
80. Subtract 4 (from 10, 12, 8)
81. Subtract 8 from 17, 13 & 11
82. Subtract 6 from 13, 15 & 11
83. Subtract 9 from 12, 15 & 17
84. Build A Total - number sequence, 11
85. What Comes Next? - 10 less than 12