BEATCALC:  Beat the Calculator!

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From the BEATCALC mailing list:
a weekly service from B. Lee Clay, archived here by the Math Forum.
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   Squaring special numbers (3's and final 5)

  1. Choose a number with repeating 3's and a final 5.
  2. The square is made up of:
    • the same number of 1's as there are repeating 3's in the number;
    • one more 2 than there are repeating 3's;
    • a final 5.

   Example:

  1. If the number to be squared is 3335:
  2. The square has:

    three 1's (same as repeating 3's)  1 1 1
    four 2's (one more than
       repeating 3's)                        2 2 2 2
    a final 5                                        5

  3. So the square of 3335 is 11,122,225.

   See the pattern?

  1. If the number to be squared is 333335:
  2. The square has:

    five 1's (same as
       repeating 3's)      1 1 1 1 1
    six 2's (one more than
       repeating 3's)                2 2 2 2 2 2
    a final 5                                     5

  3. So the square of 333335 is 111,112,222,225.


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22 December 1997
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