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 3-digit number by 143

  1. Select a 3-digit number.
  2. Repeat the 3 digits to produce a 6-digit number.
  3. Divide by 7.

   Example:

  1. The 3-digit number chosen to multiply by 143 is 123.
  2. Repeat 3 digits: 123123
  3. Divide by 7: 123123/7 = 17589
  4. So 143 x 123 = 17,589.

   See the pattern?

  1. The 3-digit number chosen to multiply by 143 is 765.
  2. Repeat 3 digits: 765765
  3. Divide by 7: 765765/7 = 109395
  4. So 143 x 765 = 109,395.


webmaster@mathforum.com
9 October 2000
Web page design by Sarah Seastone