BEATCALC:  Beat the Calculator!

___________________________________________
Back to Calculation Tips & Tricks
___________________________________________

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.


   Multiplying a 2-digit number by 1 1/6

  1. Select a 2-digit number.
  2. Multiply by 7.
  3. Divide the result by 6.

   Example:

  1. The 2-digit number chosen to multiply by 1 1/6 is 34.
  2. Multiply by 7: 7 x 34 = 210 + 28 = 238
  3. Divide by 6: 238/6 = 39 4/6
  4. So 34 x 1 1/6 = 39 2/3.

   See the pattern?

  1. If the 2-digit number chosen to multiply by 1 1/6 is 57:
  2. Multiply by 7: 7 x 57 = 350 + 49 = 399
  3. Divide by 6: 399/6 = 66 3/6
  4. So 57 x 1 1/6 = 66 1/2.


webmaster@mathforum.com
28 August 2000
Web page design by Sarah Seastone