BEATCALC:  Beat the Calculator!

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 Squaring Numbers

 Multiplying Numbers

  1. same 1st digit
  2. same 1st digit, sum 10
  3. same 2nd digit
  4. 3 digits, middle 0
  5. 3 digits, middle 1
  6. 3 digits, middle 2
  7. 3 digits, middle 3
  8. 3 digits, middle 4
  9. 3 digits, middle 5
  10. difference of 1
  11. difference of 2
  12. difference of 3
  13. difference of 4
  14. difference of 6
  15. difference of 8
  16. difference of 10
  17. 2 digits by 1 1/25
  18. 2 digits by 1.1
  19. 2 digits by 1 1/9
  20. 2 digits by 1 1/8
  21. 2 digits by 1 1/7
  22. 2 digits by 1 1/6
  23. 2 digits by 1 1/5
  24. 2 digits by 1 2/9
  25. 2 digits by 1 1/4
  26. 2 digits by 1 2/7
  27. 2 digits by 1.3
  28. 2 digits by 1 1/3
  29. 2 digits by 1 3/8
  30. 2 digits by 1 2/5
  31. 2 digits by 1 3/7
  32. 2 digits by 1 1/2
  33. 2 digits by 1 4/7
  34. 2 digits by 1 3/5
  35. 2 digits by 1.6
  36. 2,3 digits by 1 2/3
  37. 2 digits by 1 5/7
  38. 2 digits by 1 3/4
  39. 2 digits by 1 4/5
  40. 2 digits by 1 5/6
  41. 2 digits by 1 6/7
  42. 2 digits by 1.9
  43. 2 digits by 2.1
  44. 2 digits by 2 1/9
  45. 2 digits by 2 1/7
  46. 2 digits by 2 1/5
  47. 2 digits by 2 2/9
  48. 2 digits by 2 1/4
  49. 2 digits by 2.3
  50. 2 digits by 2 1/3
  51. 2 digits by 2 3/8
  52. 2 digits by 2 2/5
  53. 2 digits by 2.4
  54. 2 digits by 2 4/9
  55. 2, 3 digits by 2 1/2
  56. 2 digits by 2 4/7
  57. 2 digits by 2.6
  58. 2 digits by 2 5/8
  59. 2 digits by 2 2/3
  60. 2 digits by 2.7
  61. 2 digits by 2 5/7
  62. 2 digits by 2 3/4
  63. 2 digits by 2.8
  64. 2 digits by 2 7/9
  65. 2 digits by 2 6/7
  66. 2 digits by 2.9
  67. 2 digits by 3.1
  68. 2 digits by 3 1/8
  69. 2 digits by 3 1/7
  70. 2 digits by 3 1/6
  71. 2 digits by 3.2
  72. 2 digits by 3 2/9
  73. 2 digits by 3 1/4
  74. 2 digits by 3 1/3
  75. 2 digits by 3.4
  76. 2 digits by 3 3/7
  77. 2 digits by 3 4/9
  78. 2 digits by 3 1/2
  79. 2 digits by 3.6
  80. 2 digits by 3 4/7
  81. 2 digits by 3 5/8
  82. 2 digits by 3 2/3
  83. 2 digits by 3.7
  84. 2 digits by 3 5/7
  85. 2 digits by 3 3/4
  86. 2 digits by 3 4/5
  87. 2 digits by 3 6/7
  88. 2 digits by 3 7/8
  89. 2 digits by 3.9
  90. 2 digits by 4.1
  91. 2 digits by 4 1/4
  92. 2 digits by 4 1/7
  93. 2 digits by 4 1/6
  94. 2 digits by 4 1/5
  95. 2 digits by 4 2/7
  96. 2 digits by 4.3
  97. 2 digits by 4.4
  98. 2 digits by 4 3/7
  99. 2 digits by 4 4/9
  100. 2 digits by 4 1/2
  101. 2 digits by 4 5/9
  102. 2 digits by 4.6
  103. 2 digits by 4.7
  104. 2 digits by 4 3/4
  105. 2 digits by 4 4/5
  106. 2 digits by 4 5/6
  107. 2 digits by 4 7/8
  108. 2 digits by 5.1
  109. 2 digits by 5 1/8
  110. 2 digits by 5 1/6
  111. 2 digits by 5.2
  112. 2 digits by 5 1/4
  113. 2 digits by 5.3
  114. 2 digits by 5 4/9
  115. 2 digits by 5 1/2
  116. 2 digits by 5 5/9
  117. 2 digits by 5.6
  118. 2 digits by 5.7
  119. 2 digits by 5 4/7
  120. 2 digits by 5 5/7
  121. 2 digits by 5 4/5
  122. 2 digits by 5 6/7
  123. 2 digits by 5.9
  124. 2 digits by 6.1
  125. 2 digits by 6 1/8
  126. 2 digits by 6 1/5
  127. 2 digits by 6 1/4
  128. 2 digits by 6.3
  129. 2 digits by 6 1/3
  130. 2 digits by 6 3/8
  131. 2 digits by 6.4
  132. 2 digits by 6 4/9
  133. 2 digits by 6 1/2
  134. 2 digits by 6 5/9
  135. 2 digits by 6.6
  136. 2 digits by 6 2/3
  137. 2 digits by 6 7/9
  138. 2 digits by 6 5/6
  139. 2 digits by 6 6/7
  140. 2 digits by 6 8/9
  141. 2 digits by 7.1
  142. 2 digits by 7 1/7
  143. 2 digits by 7.2
  144. 2 digits by 7 1/4
  145. 2 digits by 7.3
  146. 2 digits by 7 2/7
  147. 2 digits by 7.4
  148. 2 digits by 7 1/2
  149. 2 digits by 7 3/5
  150. 2 digits by 7.6
  151. 2 digits by 7.7
  152. 2 digits by 7 3/4
  153. 2 digits by 7 4/5
  154. 2 digits by 8.1
  155. 2 digits by 8 1/6
  156. 2 digits by 8.2
  157. 2 digits by 8 2/7
  158. 2 digits by 8.3
  159. 2 digits by 8 1/3
  160. 2 digits by 8 3/7
  161. 2 digits by 8 4/7
  162. 2 digits by 8 1/2
  163. 2 digits by 8.6
  164. 2 digits by 8 5/8
  165. 2 digits by 8 2/3
  166. 2 digits by 8 5/7
  167. 2 digits by 8 7/9
  168. 2 digits by 8 7/8
  169. 2 digits by 8 8/9
  170. 2 digits by 9.1
  171. 2 digits by 9.2
  172. 2 digits by 9.3
  173. 2 digits by 9 1/3
  174. 2 digits by 9.4
  175. 2 digits by 9 1/2 (four steps)
  176. 2 digits by 9 1/2 (two steps)
  177. 2 digits by 9.6
  178. 2 digits by 9 2/3
  179. 2 digits by 9 5/7
  180. 2 digits by 9.7
  181. 2 digits by 9 3/4
  182. 2 digits by 9 7/9
  183. 2 digits by 9 4/5
  184. 2 digits by 9 5/6
  185. 2 digits by 9 6/7
  186. 2 digits by 9 7/8
  187. 2 digits by 9 8/9
  188. 2 digits by 10.1
  189. 2 digits by 10.4
  190. 2 digits by 10.6
  191. 2 digits by 10.7
  192. 2 digits by 10 1/2
  193. 2 digits by 11 1/2
  194. 2 digits by 12 1/2
  195. 2 digits by 15
  196. 2,3 digits by 16 2/3
  197. 2 digits by 18
  198. 2 digits by 19 1/2
  199. 2 digits by 20 1/2
  200. 2 digits by 21
  201. 2 digits by 22
  202. 2 digits by 23
  203. 2 digits by 24
  204. 2,3 digits by 25
  205. 2 digits by 26
  206. 2 digits by 27
  207. 2 digits by 28
  208. 2 digits by 29
  209. 2 digits by 29 1/2
  210. 2 digits by 30 1/2
  211. 2 digits by 31
  212. 2 digits by 32
  213. 2 digits by 33
  214. 2 digits by 33 1/3
  215. 2 digits by 34
  216. 2 digits by 35
  217. 2 digits by 36
  218. 2 digits by 37
  219. 2 digits by 37 1/2
  220. 2 digits by 38
  221. 2 digits by 39
  222. 2 digits by 39 1/2
  223. 2 digits by 40 1/2
  224. 2 digits by 42
  225. 2 digits by 43
  226. 2 digits by 44
  227. 2 digits by 45
  228. 2 digits by 46
  229. 2 digits by 47
  230. 2 digits by 48
  231. 2 digits by 49 (a)
  232. 2 digits by 49 (b)
  233. 2 digits by 49 1/2
  234. 2 digits by 50 1/2
  235. 2 digits by 51
  236. 2 digits by 52
  237. 2 digits by 53
  238. 2 digits by 54
  239. 2 digits by 55 (a)
  240. 2 digits by 55 (b)
  241. 2 digits by 56
  242. 2 digits by 57
  243. 2 digits by 58
  244. 2 digits by 59
  245. 2 digits by 59 1/2
  246. 2 digits by 60 1/2
  247. 2 digits by 61
  248. 2 digits by 62
  249. 2 digits by 63
  250. 2 digits by 64
  251. 2 digits by 65
  252. 2 digits by 66
  253. 2 digits by 67
  254. 2 digits by 68
  255. 2 digits by 69
  256. 2 digits by 69 1/2
  257. 2 digits by 70 1/2
  258. 2 digits by 71
  259. 2 digits by 72
  260. 2 digits by 73
  261. 2 digits by 74
  262. 2,3 digits by 75
  263. 2 digits by 76
  264. 2 digits by 77
  265. 2 digits by 78
  266. 2 digits by 79
  267. 2 digits by 79 1/2
  268. 2 digits by 80 1/2
  269. 2 digits by 81
  270. 2 digits by 82
  271. 2 digits by 83
  272. 2 digits by 84
  273. 2 digits by 85
  274. 2 digits by 86
  275. 2 digits by 87
  276. 2 digits by 88
  277. 2 digits by 89
  278. 2 digits by 89 1/2
  279. 2 digits by 90 1/2
  280. 2 digits by 91
  281. 2 digits by 92
  282. 2 digits by 93
  283. 2 digits by 94
  284. 2 digits by 97
  285. 2 digits by 98
  286. 2 digits by 99
  287. 3 digits by 99
  288. 2,3 digits by 101
  289. 2 digits by 102 + 11
  290. 2 digits by 103 + 12
  291. 2 digits by 125
  292. 3 digits by 143
  293. 2 digits by 166 2/3
  294. 2 digits by 198
  295. 2 digits by 201 + 11
  296. 2 digits by 202 + 11
  297. 2 digits by 250
  298. 2 digits by 297
  299. 2 digits by 375
  300. 2 digits by 396
  301. 2 digits by 495
  302. 2 digits by 594
  303. 2 digits by 625
  304. 2 digits by 693
  305. 2 digits by 792
  306. 2 digits by 875
  307. 2 digits by 891
  308. 2 digits by 999
  309. 2,3 digits by 1001 + 21,201
  310. 2-4 digits by 1000, + 21, 201, 2001
  311. 2-5 digits by 100001
  312. 1 rep. by 9 rep.
  313. 1 rep. by 12 rep.
  314. 1 rep. by 13 rep.
  315. 1 rep. by 14 rep.
  316. 1 rep. by 15 rep.
  317. 1 rep. by 16 rep.
  318. 1 rep. by 17 rep.
  319. 1 rep. by 18 rep.
  320. 1 rep. by 19 rep.
  321. 1 rep. by 21
  322. 1 rep. by 22
  323. 1 rep. by 23
  324. 1 rep. by 24
  325. 1 rep. by 25
  326. 1 rep. by 26
  327. 1 rep. by 27
  328. 1 rep. by 29
  329. 1 rep. by 33
  330. 1 rep. by 41
  331. 1 rep. by 44
  332. 1 rep. by 45
  333. 1 rep. by 55
  334. 1 rep. by 66
  335. 1 rep. by 77
  336. 1 rep. by 88
  337. 1 rep. by 99
  338. 1 rep. by 222
  339. 1 rep. by 333
  340. 2 rep. by 5 rep.
  341. 2 rep. by 9 rep.
  342. 2 rep. by 12
  343. 2 rep. by 13
  344. 2 rep. by 14
  345. 2 rep. by 15
  346. 2 rep. by 16
  347. 2 rep. by 17
  348. 2 rep. by 22
  349. 2 rep. by 24
  350. 2 rep. by 28
  351. 2 rep. by 33
  352. 2 rep. by 44
  353. 2 rep. by 45
  354. 2 rep. by 55
  355. 2 rep. by 66
  356. 2 rep. by 77
  357. 2 rep. by 88
  358. 2 rep. by 99
  359. 3 rep. by 6 rep.
  360. 3 rep. by 9 rep.
  361. 3 rep. by 13
  362. 3 rep. by 15
  363. 3 rep. by 22
  364. 3 rep. by 23
  365. 3 rep. by 24
  366. 3 rep. by 35
  367. 3 rep. by 55
  368. 3 rep. by 66
  369. 3 rep. by 77
  370. 3 rep. by 88
  371. 3 rep. by 99
  372. 4 rep. by 15
  373. 4 rep. by 17
  374. 4 rep. by 22
  375. 4 rep. by 24
  376. 4 rep. by 28
  377. 4 rep. by 31
  378. 4 rep. by 36
  379. 4 rep. by 42
  380. 4 rep. by 44
  381. 4 rep. by 55
  382. 4 rep. by 88
  383. 4 rep. by 3 rep.
  384. 4 rep. by 5 rep.
  385. 4 rep. by 9 rep.
  386. 5 rep. by 25
  387. 5 rep. by 28
  388. 5 rep. by 33
  389. 5 rep. by 55
  390. 5 rep. by 66
  391. 5 rep. by 88
  392. 5 rep. by 9 rep.
  393. 6 rep. by 9 rep.
  394. 6 rep. by 12
  395. 6 rep. by 16
  396. 6 rep. by 22
  397. 6 rep. by 31
  398. 6 rep. by 32
  399. 6 rep. by 33
  400. 6 rep. by 43
  401. 6 rep. by 55
  402. 6 rep. by 66
  403. 6 rep. by 77
  404. 6 rep. by 88
  405. 6 rep. by 444
  406. 6 rep. by 888
  407. 7 rep. by 9 rep.
  408. 7 rep. by 17
  409. 7 rep. by 32
  410. 7 rep. by 33
  411. 7 rep. by 42
  412. 7 rep. by 44
  413. 7 rep. by 55
  414. 7 rep. by 88
  415. 8 rep. by 9 rep.
  416. 8 rep. by 22
  417. 8 rep. by 23
  418. 8 rep. by 29
  419. 8 rep. by 36
  420. 8 rep. by 44
  421. 8 rep. by 55
  422. 8 rep. by 66
  423. 8 rep. by 88
  424. 9 rep. by 14
  425. 9 rep. by 22
  426. 9 rep. by 25
  427. 9 rep. by 27
  428. 9 rep. by 33
  429. 9 rep. by 44
  430. 9 rep. by 55
  431. 9 rep. by 77
  432. 9 rep. by 99
  433. 3 repeating by 2, /37
  434. 3 repeating by 5, /37
  435. 9 rep. by 3, /12345679
  436. multi-digits by 8 + last digit
  437. by 8, add number, - 20
  438. integer + 1/2 times, + 1
  439. sum,difference of 2,1 digits
  440. two mixed numbers
  441. two mixed numbers,fractions
  442. 4 digits by 99
  443. 4 digits by 137, then 73; -1200
  444. 5 digits by 9091, then 11; -1200

 Dividing Numbers

 Adding Numbers

 Subtracting Numbers

 Finding Percents

Calculation
Practice Exercises

Full List


   Multiplying two 2-digit numbers
            (same 2nd digit)

  1. Both numbers should have the same second digit.
  2. Choose first digits whose sum is 10.
  3. Multiply the first digits and add one second: X X _ _.
  4. Multiply the second digits together: _ _ X X.

   Example:

  1. If the first number is 67, choose 47 as the second number (same second digit, first digits add to 10).
  2. Multiply the 1st digits, add one 2nd.
    6x4 = 24, 24+7 = 31. 3 1 _ _
  3. Multiply the 2nd digits. 7x7 = 49 _ _ 4 9
  4. So 67 × 47 = 3149.

   See the pattern?

  1. If the first number is 93, choose 13 as the second number (same second digit, first digits add to 10).
  2. Multiply the 1st digits, add one 2nd. 9x1 = 9, 9+3 = 12.
    1 2 _ _
  3. Multiply the 2nd digits. 3x3 = 9 _ _ 0 9
  4. So 93 × 13 = 1209.


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3 November 1997
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