BEATCALC:  Beat the Calculator!

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Back to Calculation Tips & Tricks
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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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   Multiplying a 2-digit number by 33 1/3

  1. Select a 2-digit number .
  2. Add two zeros.
  3. Divide by 3.

   Example:

  1. The 2-digit number chosen to multiply by 33 1/3
    is 48.
  2. Add two zeros: 4800
  3. Divide by 3: 4800/3 = 1600
  4. So 48 x 33 1/3 = 1600.

   See the pattern?

  1. The 2-digit number chosen to multiply by 33 1/3
    is 92.
  2. Add two zeros: 9200
  3. Divide by 3: 9200/3 = 3066 2/3.
  4. So 92 x 33 1/3 = 3066 2/3.


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29 September 1997
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