Apply known single-digit addition and subtraction facts to mental strategies for addition and subtraction of two-, three- and four-digit numbers, including:the jump strategy on an empty number line, the split strategy, the compensation strategy, using pat
| 1. | Changing Numbers: 100 to 200 | |
| 2. | Changing Numbers: 265 to 255 | |
| 3. | Changing Numbers: 550 to 650 | |
| 4. | Changing Numbers: 300 to 299 | |
| 5. | Changing Numbers: 888 to 898 | |
| 6. | Changing Numbers: 428 to 438 | |
| 7. | Changing Numbers: 204 to 194 | |
| 8. | Changing Numbers: 402 to 412 | |
| 9. | Changing Numbers: 399 to 499 | |
| 10. | Changing Numbers - 45 to 145 | |
| 11. | Changing Numbers - 235 to 225 | |
| 12. | Changing Numbers - 990 to 890 | |
| 13. | Changing Numbers - 576 to 577 | |
| 14. | Changing Numbers - 36 to 136 | |
| 15. | Changing Numbers - 455 to 555 | |
| 16. | 1000 less, 1000 more than 4215 | |
| 17. | 1000 less, 1 more than 7999 | |
| 18. | 1000 less, 1000 more than 3690 | |
| 19. | Changing Numbers - 2458 to 2558 | |
| 20. | Changing Numbers - 9906 to 9996 | |
| 21. | Changing Numbers - 7899 to 7909 | |
| 22. | Changing Numbers - 4323 to 4423 | |
| 23. | Changing Numbers - 8999 to 9000 | |
| 24. | 1000 less, 100 more than 4035 | |
| 25. | 1000 less, 100 more than 1000 | |
| 26. | 1000 less, 1000 more than 1900 | |
| 27. | 100 less, 1000 more than 1795 | |
| 28. | 1000 less, 10 more than 8712 | |
| 29. | 1000 less, 100 more than 6995 | |
| 30. | 100 less, 1 more than 5999 | |
| 31. | 1000 less, 1 more than 8799 | |
| 32. | 100 less, 1000 more than 5000 | |
| 33. | 1 less, 1000 more than 8000 | |
| 34. | Changing Numbers - 1040 to 1140 | |
| 35. | Changing Numbers - 820 to 1820 | |
| 36. | 1000 less, 100 more than 6793 | |
| 37. | 1000 less, 1 more than 3589 | |
| 38. | Add these 3 numbers: 14 + 5 + 2 | |
| 39. | Add these 3 numbers: 11 + 4 + 5 | |
| 40. | Add these 3 numbers: 13 + 7 + 6 | |
| 41. | Same or Different? Click all boxes with answer 20 | |
| 42. | Adding tens: 42 + 10 = ? | |
| 43. | Adding tens: 38 + 20 = ? | |
| 44. | Adding tens: 56 + 30 = ? | |
| 45. | Changing numbers 136 to 140 | |
| 46. | Changing numbers 122 to 130 | |
| 47. | Changing numbers 154 to 160 | |
| 48. | Changing numbers 188 to 190 | |
| 49. | Changing numbers 177 to 180 | |
| 50. | Add three numbers: 14 + 7 + 3 | |
| 51. | Add three numbers: 20 + 10 + 20 | |
| 52. | 40s zone: Add on 5 to 36. | |
| 53. | 40s zone: 4 more than 38 | |
| 54. | 40s zone: 37 plus 5 | |
| 55. | 40s zone: 4 more than 39 | |
| 56. | 40s zone: Add on 3 to 38 | |
| 57. | 50s zone: Add on 5 to 47. | |
| 58. | 50s zone: 49 plus 3 | |
| 59. | 50s zone: 48 plus 5 | |
| 60. | 50s zone: 4 more than 47 | |
| 61. | 50s zone: 5 more than 46 | |
| 62. | Number Detectives: 10 + 20 = ? | |
| 63. | Use the pattern: 2+4, 12+4, 120 + 40 | |
| 64. | Use the pattern: 4+1, 14+1, 140+10 | |
| 65. | Use The Pattern: 4+3, 14+3, 140+30 | |
| 66. | Use The Pattern: 2+7, 12+7, 120+70 | |
| 67. | Use The Pattern: 5+4, 15+4, 150+40 | |
| 68. | Use The Pattern: 3+6, 13+6, 130+60 | |
| 69. | Use The Pattern: 5+3, 15+3, 150+30 | |
| 70. | Beyond 20: What is 6 more than 29? | |
| 71. | Beyond 50: What is 4 more than 57? | |
| 72. | Beyond 70: What is 8 more than 78? | |
| 73. | Beyond 30: What is 4 more than 38? | |
| 74. | Beyond 60: What is 5 more than 68? | |
| 75. | Addition Chains: 10 + 4 + 6 + 2, 11 + 2 + 3 + 4 | |
| 76. | Addition Chains: 4 + 5 + 5 + 2, 10 + 5 + 5 + 10 | |
| 77. | Addition Chains: 3 + 2 + 4 + 2, 7 + 2 + 3 + 4 | |
| 78. | Add three numbers: 14 + 12 + 8 | |
| 79. | Crossing 100: 4 more than 99 | |
| 80. | Crossing 100: 7 more than 97 | |
| 81. | Crossing 100: 8 more than 98 | |
| 82. | Crossing 100: 9 more than 92 | |
| 83. | Crossing 100: 5 more than 97 | |
| 84. | Same or Different: Click all the boxes with the answer 50. | |
| 85. | Same or Different: Click all the boxes with the answer 46. | |
| 86. | Same or Different: Click all the boxes with the answer 32. | |
| 87. | Same or Different: Click all the boxes with the answer 45. | |
| 88. | Same or Different: Click all the boxes with the answer 38. | |
| 89. | Beyond 40: 6 more than 45 | |
| 90. | Beyond 70: 5 more than 79 | |
| 91. | Beyond 60: 8 more than 68 | |
| 92. | Beyond 50: 7 more than 58 | |
| 93. | Beyond 70: 9 more than 72 | |
| 94. | Changing Numbers 29 to 34 | |
| 95. | Changing Numbers 67 to 78 | |
| 96. | Changing Numbers 98 to 101 | |
| 97. | Changing Numbers 87 to 92 | |
| 98. | Changing Numbers 59 to 63 | |
| 99. | Changing Numbers 96 to 101 | |
| 100. | Changing Numbers 98 to 105 | |
| 101. | Changing Numbers 97 to 103 | |
| 102. | Changing Numbers 97 to 102 | |
| 103. | Changing Numbers 99 to 103 | |
| 104. | Changing Numbers 42 to 62 | |
| 105. | Changing Numbers 63 to 93 | |
| 106. | Changing Numbers 14 to 54 | |
| 107. | Changing Numbers 137 to 157 | |
| 108. | Changing Numbers 35 to 85 | |
| 109. | Number detectives 235+6 = * | |
| 110. | Number detectives 98+7=* | |
| 111. | Use The Pattern 3+5 30+50 300+500 | |
| 112. | Use The Pattern 3+6 30+60 600+300 | |
| 113. | Use The Pattern 2+4 20+40 200+400 | |
| 114. | Use The Pattern 3+2 30+20 200+300 | |
| 115. | Use The Pattern 6+2 60+20 600+200 | |
| 116. | Addition Chains 21 + 3 + 6 + 5, 60 + 4 + 3 + 2 | |
| 117. | Addition Chains 33 + 4 + 10 + 5, 28 + 3 + 9 + 8 | |
| 118. | Addition Chains 23 + 5 + 4 + 9, 60 + 8 + 3 + 10 | |
| 119. | Addition Chains 95 + 4 + 2 + 12, 94 + 3 + 3 + 7 | |
| 120. | Addition Chains 100 + 5 + 5 + 7, 99 + 3 + 6 + 2 | |
| 121. | Beyond 90: 98 + 4 | |
| 122. | Beyond 100: 104 + 7 | |
| 123. | Beyond 110: 119+3 | |
| 124. | Beyond 120: 128+6 | |
| 125. | Beyond 130: 139 + 5 | |
| 126. | Changing numbers: 12 + 10, +11, +111 | |
| 127. | Changing numbers: 28 + 10, +11, +111 | |
| 128. | Changing numbers: 49 + 10, +11, +111 | |
| 129. | Changing numbers: 88 + 10, +11, +111 | |
| 130. | Changing numbers: 29 + 10, +11, +111 | |
| 131. | Number Detectives: 100 Pairs 63 + 37 = ? | |
| 132. | Use the pattern: 6+3, 60+30, 600+300 | |
| 133. | Use the pattern: 2+4, 20+40, 200+400 | |
| 134. | Use the pattern: 2+6, 20+60, 200+600 | |
| 135. | Use the pattern: 4+9, 40+90, 400+900 | |
| 136. | Use the pattern: 1+7, 10+70, 100+700 | |
| 137. | Adding Tens: 416 + 50 = * | |
| 138. | Adding Tens: 542 + 50 = * | |
| 139. | Add Hundreds: 500+246 | |
| 140. | Add Hundreds: 100+280 | |
| 141. | Add Hundreds: 300+453 | |
| 142. | Add Hundreds: 200+43 | |
| 143. | Add Hundreds: 800+163 | |
| 144. | Mystery number: 106+11=? | |
| 145. | Mystery number: 514+12=? | |
| 146. | Mystery number: 913+13=? | |
| 147. | Mystery number: 711+17=? | |
| 148. | Mystery number: 133+16=? | |
| 149. | Use the pattern: 5+2,50+20, 500+200=? | |
| 150. | Use the pattern: 5+4,50+40, 500+400=? | |
| 151. | Use the pattern: 7+1,70+10, 700+100=? | |
| 152. | Use the pattern: 2+3,20+30, 200+300=? | |
| 153. | Use the pattern: 3+8,30+80, 300+800=? | |
| 154. | Same or different:19-12,2+5,3+4,33-26,16-8 | |
| 155. | Same or different:13-4,6+3,12-5,19-8,32-23 | |
| 156. | Same or different:44-8,14+23,22+18,19+17,54-18 | |
| 157. | Same or different:43-7,21+17,13+22,18+16,53-17 | |
| 158. | Same or different:13+6,34-15,43-25,32-13,58-37 | |
| 159. | Adding Tens: 235+50 =? | |
| 160. | Adding Tens: 338+50=? | |
| 161. | Adding Tens: 562+30=? | |
| 162. | Taking tens: 40 - 30 = ? | |
| 163. | Taking tens: 50 - 20 = ? | |
| 164. | Taking tens: 80 - 40 = ? | |
| 165. | Taking tens: 70 - 10 = ? | |
| 166. | Taking tens: 70 - 40 = ? | |
| 167. | Taking tens: 40 - 30 = ? | |
| 168. | Subtraction Chain - 29-8=21-3=? | |
| 169. | Subtraction Chain - 26-5=21-4=? | |
| 170. | Use the pattern: 10, 20 & 80 - 5 = ? | |
| 171. | Use the pattern: 10, 20 & 40 - 3 = ? | |
| 172. | Use the pattern: 10, 20 & 90 - 7 = ? | |
| 173. | Use the pattern: 10, 20 & 50 - 4 = ? | |
| 174. | Use the pattern: 10, 20 & 30 - 8 = ? | |
| 175. | Taking ten: 46-10 | |
| 176. | Taking ten: 72-10 | |
| 177. | Taking ten: 39-10 | |
| 178. | Taking ten: 55-10 | |
| 179. | Taking ten: 81-10 | |
| 180. | Use the pattern 16-7=? 26-7=?, 36-7=? | |
| 181. | Use the pattern 13-6=? 23-6=?, 33-6=? | |
| 182. | Use the pattern 11-5=? 21-5=?, 31-5=? | |
| 183. | Use the pattern 12-9=? 22-9=?, 32-9=? | |
| 184. | Use the pattern 19-4=? 29-4=?, 39-4=? | |
| 185. | Use the pattern 17-8=? 27-8=?, 37-8=? | |
| 186. | Same Difference - Difference between 10 and 40. | |
| 187. | Number detectives: 30 - 14 = ? | |
| 188. | Use the pattern: 9-5, 90-50, 900-500 | |
| 189. | Use the pattern: 8-5, 80-50, 800-500 | |
| 190. | Use the pattern: 6-2, 60-20, 600-200 | |
| 191. | Use the pattern: 9-8, 90-80, 900-800 | |
| 192. | Use the pattern: 5-3, 50-30, 500-300 | |
| 193. | Use the pattern: 8-2, 80-20, 800-200 | |
| 194. | Count Down: 6 less than 41 | |
| 195. | Count Down: 7 less than 52 | |
| 196. | Count Down: 3 less than 42 | |
| 197. | Count Down: 6 less than 43 | |
| 198. | Count Down: 8 less than 47 | |
| 199. | Taking Tens: 44 - 20 | |
| 200. | Taking Tens: 68 - 30 | |
| 201. | Taking Tens: 98 - 50 | |
| 202. | Taking Tens: 32 - 20 | |
| 203. | Taking Tens: 59 - 40 | |
| 204. | Taking Tens: 87 - 20 | |
| 205. | Taking Tens: 72 - 40 | |
| 206. | Subtract.chains 48 - 7 - 2 - 9, 35 - 4 - 3 - 8 | |
| 207. | Subtract.chains 47 - 4 - 3 - 7, 28 - 8 - 2 - 5 | |
| 208. | Subtract.chains 23 - 4 - 1 - 3, 36 - 5 - 2 - 6 | |
| 209. | Subtract.chains 32 - 4 - 7 - 4, 45 - 2 - 10 - 5 | |
| 210. | Subtract.chains 28 - 5 - 2 - 10, 50 - 5 - 3 - 2 | |
| 211. | Spot the difference: 102 & 97, 27 & 19, 100 & 60 | |
| 212. | Changing Numbers 55-37=? | |
| 213. | Changing Numbers 65-54=? | |
| 214. | Changing Numbers 48-22=? | |
| 215. | Changing Numbers 36-16=? | |
| 216. | Changing Numbers 51-28=? | |
| 217. | Changing Numbers 42-32=? | |
| 218. | Number Detectives: 30 - 17 = ? | |
| 219. | Number Detectives: 30 - 14 = ? | |
| 220. | Count down 52-4=? | |
| 221. | Count down 43-6=? | |
| 222. | Count down 61-5=? | |
| 223. | Count down 36-8=? | |
| 224. | Count down 72-7=? | |
| 225. | Count down 94-9=? | |
| 226. | Take Ten 42 - 10 | |
| 227. | Subtraction chains 80-6-5-3, 70-4-2-5 | |
| 228. | Subtraction chains 30-9-2-5, 60-5-4-3 | |
| 229. | Subtraction chains 40-5-6-3, 50-9-2-8 | |
| 230. | Subtraction chains 90-3-5-3, 40-2-8-5 | |
| 231. | Subtraction chains 60-9-2-3, 50-3-6-10 | |
| 232. | Find first number: After I count back 5, the new number is 299. Where did I start? | |
| 233. | Find first number: After I count back 4, the new number is 197. Where did I start? | |
| 234. | Find first number: After I count back 6, the new number is 395. Where did I start? | |
| 235. | Find first number: After I count back 7, the new number is 596. Where did I start? | |
| 236. | Find first number: After I count back 8, the new number is 95. Where did I start? | |
| 237. | Changing Numbers 84 to 63 | |
| 238. | Changing Numbers 100 to 44 | |
| 239. | Changing Numbers 40 to 24 | |
| 240. | Changing Numbers 124 to 98 | |
| 241. | Use the Pattern: 7-3, 37-3, 167-3=? | |
| 242. | Use the Pattern: 9-5, 29-5, 249-5=? | |
| 243. | Use the Pattern: 6-3, 36-3, 166-3=? | |
| 244. | Use the Pattern: 8-1, 18-1, 128-1=? | |
| 245. | Use the Pattern: 6-4, 46-4, 286-4=? | |
| 246. | Subtracting tens 55 - 20 = ? | |
| 247. | Subtracting tens 48 - 20 = ? | |
| 248. | Subtracting tens 72 - 30 = ? | |
| 249. | Subtracting tens 87 - 60 = ? | |
| 250. | Subtracting tens 91 - 60 = ? | |
| 251. | Subtraction chains: 30-4-16-8, 30-5-3-11 | |
| 252. | Subtraction chains: 30-3-4-13, 30-6-5-7 | |
| 253. | Subtraction chains: 30-10-9-4, 30-5-9-7 | |
| 254. | Changeover: 7 less than 301 | |
| 255. | Changeover: 6 less than 904 | |
| 256. | Changeover: 6 less than 503 | |
| 257. | Changeover: 7 less than 204 | |
| 258. | Changeover: 8 less than 305 | |
| 259. | Spot the Difference: Between 169 and 176 | |
| 260. | Spot the Difference: Between 239 and 242 | |
| 261. | Spot the Difference: Between 465 and 472 | |
| 262. | Spot the Difference: Between 327 and 333 | |
| 263. | Spot the Difference: Between 689 and 694 | |
| 264. | Spot the difference: 160 and 174; 346 and 360; 190 and 204 | |
| 265. | Same or Different: Answer 43 | |
| 266. | Same or Different: Answer 77 | |
| 267. | Same or Different: Answer 69 | |
| 268. | Same or Different: Answer 56 | |
| 269. | Same or Different: Answer 38 | |
| 270. | Same or Different: Answer 24 | |
| 271. | Build A Total - number sequence, 24 | |
| 272. | Enid the Elephant's Equations - equivalent to 8 + 4 | |
| 273. | Enid the Elephant's Equations - equivalent to 6 + 5 | |
| 274. | Enid the Elephant's Equations - equivalent to 7 + 7 | |
| 275. | Dr Dan's Number Operations - "x - 6 = 7" | |
| 276. | Number Quest - find 1 number to complete 2 number sentences | |
| 277. | Sign Scramble - complete 2 number sentences using given numbers | |
| 278. | Build A Total - number sequence, 24 | |
| 279. | Build A Total - number sequence, 45 | |
| 280. | Build A Total - number sequence, 30 | |
| 281. | Build a Total - number sequence, 15 | |
| 282. | Number Quest - find 1 number to complete 2 number sentences | |
| 283. | Number Quest - find 1 number to complete 2 number sentences | |
| 284. | A Tall Order - 5 more | |
| 285. | Weigh Ho, Me Hearties! - adding masses in kg | |
| 286. | Crossing 100: Add 70 to 60 | |
| 287. | Crossing 100: Add 60 to 80 | |
| 288. | Crossing 100: Add 90 to 40 | |
| 289. | Crossing 100: Add 50 to 90 | |
| 290. | Crossing 100: Add 50 to 70 | |
| 291. | The Chicken Story: forty-one - thirty-three | |
| 292. | The Chicken Story: seventy-six - sixty-five | |
| 293. | 100 less, 1000 more than 2231 | |
| 294. | 1000 less, 100 more than 4550 | |
| 295. | Build A Total - number sequence, 40 | |
| 296. | Build A Total - number sequence, 50 | |
| 297. | Build A Total - number sequence, 55 | |
| 298. | Build A Total - number sequence, 25 | |
| 299. | Build A Total - number sequence, 35 | |
| 300. | 1000 less, 1000 more than 1001 | |
| 301. | 1000 less, 1000 more than 4035 |