BEATCALC:  Beat the Calculator!

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Back to Calculation Tips & Tricks
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Calculation Practice from the BEATCALC mailing list:
a weekly service from B. Lee Clay, archived here by the Math Forum.
To subscribe to the BEATCALC mailing list, write to BEATCALC@aol.com.

Here are some of the calculations that you can do mentally after practicing the BEATCALC exercises. See how many you can do. Check your answers with a calculator. Your mental math powers should be impressive!

   15 x 15      89 x 89     394 x 101     32 x 38      51 x 59
  101 x 147    101 x 94      93 x 93     228 x 101     25 x 25
   56 x 56      94 x 96     101 x 448     83 x 87     687 x 101
   64 x 66      52 x 52     101 x 654     35 x 35      11 x 19
  101 x 206     61 x 69      89 x 101     61 x 61      34 x 36
  101 x 48      52 x 52      45 x 45     456 x 101     54 x 54
   41 x 41     101 x 41      32 x 32      83 x 101     29 x 29
   55 x 55      63 x 67     479 x 101     82 x 82     882 x 101
   14 x 16     319 x 101     73 x 77      65 x 65     101 x 859
   13 x 17     101 x 149     41 x 49      82 x 101     75 x 75
  101 x 144     71 x 79      69 x 101     22 x 22     993 x 101
   51 x 51      85 x 85     101 x 101    129 x 101     69 x 69
   31 x 39     738 x 101     21 x 29      71 x 71      77 x 101
   95 x 95     265 x 101     74 x 76      53 x 53     101 x 409
   51 x 51      98 x 101     94 x 94      42 x 42      53 x 57
  339 x 101     62 x 68     101 x 88      19 x 19     238 x 101
   43 x 47      96 x 96      21 x 21     101 x 279     81 x 89
  648 x 101     62 x 62     101 x 57      24 x 26     101 x 668
   99 x 99      23 x 27      22 x 28     515 x 101     97 x 97
   79 x 79     101 x 826    245 x 101     31 x 31      37 x 33
  101 x 218     82 x 88      39 x 39     126 x 101     91 x 99
   68 x 101     51 x 101    598 x 101     98 x 98      72 x 72
   91 x 91      54 x 56     101 x 29      57 x 57     771 x 101
   81 x 81     559 x 101     52 x 58      59 x 59      84 x 86
   46 x 44     101 x 25      12 x 18     101 x 697     92 x 92
  349 x 101     93 x 97     101 x 188     42 x 48      49 x 49
  101 x 388     58 x 58      92 x 92     101 x 78      37 x 101

How many could you do quickly and accurately?

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