Add and subtract numbers mentally with increasingly large numbers
| 1. | 100 less, 100 more than 69 582 | |
| 2. | Changing Numbers: Add 100, 1000, 10 000 to 33 125 | |
| 3. | Changing Numbers: Add 100, 1000, 10 000 to 78 244 | |
| 4. | Changing Numbers: Add 1000, 10 000, 100 000 to 213 426 | |
| 5. | Changing Numbers: Add 1000, 10 000, 100 000 to 423 846 | |
| 6. | 1000 less, 100 more than 5 268 635 | |
| 7. | 100 less, 1000 more than 453 369 | |
| 8. | 1000 less, 10 more than 317 691 | |
| 9. | 10 less, 1000 more than 8 254 146 | |
| 10. | 1000 less, 1000 more than 6 325 478 | |
| 11. | 1000 less, 100 more than 2 135 698 | |
| 12. | 10 000 less, 1000 more than 9 630 258 | |
| 13. | 10 000 less, 100 000 more than 9 654 128 | |
| 14. | 1000 less, 1000 more than 6 598 696 | |
| 15. | Mystery number: 106+11=? | |
| 16. | Mystery number: 514+12=? | |
| 17. | Mystery number: 913+13=? | |
| 18. | Mystery number: 711+17=? | |
| 19. | Mystery number: 133+16=? | |
| 20. | Number detectives: 102+98=? | |
| 21. | True or False?: 63+8=65+6 | |
| 22. | True or False?: 26+7=29+4 | |
| 23. | Same or different: Click all the boxes with the same answer. | |
| 24. | Same or different: Click all the boxes with the same answer. | |
| 25. | Same or different: Click all the boxes with the same answer. | |
| 26. | Same or different: Click all the boxes with the same answer. | |
| 27. | Same or different: Click all the boxes with the same answer. | |
| 28. | True or False? Click all the number sentences that are true. | |
| 29. | True or False? Click all the number sentences that are true. | |
| 30. | True or False? Click all the number sentences that are true. | |
| 31. | True or False? Click all the number sentences that are true. | |
| 32. | True or False? Click all the number sentences that are true. | |
| 33. | True or False? Click all the number sentences that are true. | |
| 34. | Changing numbers: 36 159 add 100 add 1 add 10 | |
| 35. | Changing numbers: 23 855 add 100 add 1 add 10 | |
| 36. | Changing numbers: 36 052 add 1000 add 1 add 10 | |
| 37. | Changing numbers: 23 615 add 1000 add 100 add 10 | |
| 38. | Changing numbers: 36 925 add 10 add 1000 add 1 | |
| 39. | True or False: Double-sided equations | |
| 40. | True or False: Double-sided equations | |
| 41. | True or False: Double-sided equations | |
| 42. | True or False: Double-sided equations | |
| 43. | True or False: Double-sided equations | |
| 44. | Add these 3 numbers: 40 + 70 + 20 | |
| 45. | Add these 3 numbers: 30 + 20 + 90 | |
| 46. | Add these 3 numbers: 70 + 90 + 10 | |
| 47. | Same or different : Click all the boxes with the same answer. | |
| 48. | Same or different : Click all the boxes with the same answer. | |
| 49. | Same or different : Click all the boxes with the same answer. | |
| 50. | Same or different : Click all the boxes with the same answer. | |
| 51. | Same or different : Click all the boxes with the same answer. | |
| 52. | T/f Double sided eqns | |
| 53. | T/f Double sided eqns | |
| 54. | T/f Double sided eqns | |
| 55. | T/f Double sided eqns | |
| 56. | T/f Double sided eqns | |
| 57. | Number detectives: Four's no chore - Add 4 clustered numbers | |
| 58. | Number detectives: Four's no chore - Add 4 clustered numbers | |
| 59. | Number detectives: Four's no chore - Add 4 clustered numbers | |
| 60. | Same or different: Click all the boxes with the same answer | |
| 61. | Same or different: Click all the boxes with the same answer | |
| 62. | Same or different: Click all the boxes with the same answer | |
| 63. | Same or different: Click all the boxes with the same answer | |
| 64. | Same or different: Click all the boxes with the same answer | |
| 65. | T/F double sided: 56+14=35+35, etc | |
| 66. | T/F double sided: 23+12=65+30, etc | |
| 67. | T/F double sided: 21+80=92-42, etc | |
| 68. | T/F double sided: 42+46=19+69 | |
| 69. | T/F double sided: 32+18=25+25 | |
| 70. | Number detectives: Add 4 clustered tens numbers | |
| 71. | Number detectives: Add 4 clustered tens numbers | |
| 72. | Number detectives: Add 4 clustered tens numbers | |
| 73. | True or False?: 15 - 5 = 30 - 20 | |
| 74. | True or False?: 30 - 5 = 28 - 3 | |
| 75. | True or False?: 12-8=11-7 | |
| 76. | True or False?: 99-66=44-11 | |
| 77. | True or False?: 50-5=90-45 | |
| 78. | True or False?: 35-15=40-20 | |
| 79. | Same or different: Click all boxes with the answer 126 | |
| 80. | Same or different: Click all boxes with the answer 175 | |
| 81. | Same or different: Click all boxes with the answer 146 | |
| 82. | Same or different: Click all boxes with the answer 194 | |
| 83. | True or False?: 118 - 25 = 243 - 150 | |
| 84. | Same or different: Click all boxes with the same answer | |
| 85. | Same or different: Click all boxes with the same answer | |
| 86. | Same or different: Click all boxes with the same answer | |
| 87. | Same or different: Click all boxes with the same answer | |
| 88. | Same or different: Click all boxes with the same answer | |
| 89. | True or False: 631-82=549 | |
| 90. | True or False: 297=342-45 | |
| 91. | True or False: 746-53=693 | |
| 92. | Same or Different - Click all the boxes where the answer is 84 | |
| 93. | Same or Different - Click all the boxes where the answer is 387 | |
| 94. | Same or Different - Click all the boxes where the answer is 792 | |
| 95. | True/false: 128-64=145-81 | |
| 96. | True/false: 154-72=172-90 | |
| 97. | True/false: 136-61=125-50 |