Comments on NumbersNearMultiplesOfTen

  1. ## 50 Comments. ### How to do 56 x 49? I can't get the result.

-- Jiggaboo 2009-09-15 21:42 UTC


@Jiggaboo that's because it only works if the numbers are "close" to a POWER of 10 (not a multiple)... and yours aren't.

I have some multiplication tricks of my own at: http://www.discreteideas.com/2009/08/the-shortest-path/

-- The Count 2009-10-06 14:52 UTC


what determines a + or - in the first step?

-- Anonymous 2009-10-29 08:04 UTC


base 50 = 10 * 5

56 +6 [56 - 50 = 6] 49 -1 [49 - 50 = -1]

5 * (50 + 6 - 1) | -6 275 |-6 2750 - 6 = 2744

-- Anon. 2009-11-15 09:21 UTC


Vedic Math... early 20th century?? Sure about that?

-- anon42 2010-04-03 17:01 UTC


This is an amazing method.

-- Anonymous 2011-02-06 03:00 UTC


"Vedic Math... early 20th century?? Sure about that?"

Yep. http://en.wikipedia.org/wiki/Bharati_Krishna_Tirthaji

-- jsryan 2012-09-06 22:58 UTC