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• Aboslutely right, the next step is to gain speed and that comes with practice and in so doing I hope to memorize quickly the multiplication table from 13 to 99
Message 1 of 4 , Feb 21, 2009
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Aboslutely right, the next step is to gain speed and that comes with practice and in so doing I hope to memorize quickly the multiplication table from 13 to 99 (as I already know as most people the 1 to 12 tables). Thanks!

[ODia]

________________________________
From: John Morrison <jfm1061@...>
To: wwbc@yahoogroups.com
Sent: Sunday, February 22, 2009 3:43:31 AM
Subject: Re: [wwbc] Correction

Thank you for your kind words. We both are in agreement with doing math from the left and not the right side. The next step in this method is to do the math entirely in your head. For example, I would look at 34*36, and quickly think "9 is the leftmost number". The hidden number is 30, (18 + 12). 9 + 30 = 120 which is the partial answer. 24 is the rightmost number. Final answer 34*36 = 1224. Most times I can calculate the problem in 10 seconds.

--- On Sat, 2/21/09, Oumarou DIA <oumardia@yahoo. com> wrote:

From: Oumarou DIA <oumardia@yahoo. com>
Subject: [wwbc] Correction
To: wwbc@yahoogroups. com
Date: Saturday, February 21, 2009, 4:10 AM

1. The idea of 'right' is great, it is the multiplication of the 'leftmost' digits should be rightmost digits
2. The idea of 'left' is equally great, it is the multiplication of the 'rightmost' digitsshould be lefttmost digitsSorry for the inconvenience

[ODia]

----- Forwarded Message ----
From: Oumarou DIA <oumardia@yahoo. com>
To: wwbc@yahoogroups. com
Sent: Friday, February 20, 2009 8:26:21 PM
Subject: Re: [wwbc] Hidden Numbers or Center Numbers

Thank Thank you very much you are a genius. And that
is what geniuses do; they do the theoretical thinking and then come the regular
guys like me toy and struggle with the idea and try to simplify it.
What do you think of below?

1. The idea of 'right' is great, it is the
multiplication of the 'leftmost' digits
2. The idea of 'left' is equally great, it is the
multiplication of the 'rightmost' digits
3. The idea of 'hidden numbers' can be made
easier to understand; I propose to call them the 'Center Numbers'. It is the
addition of a)the multiplication of the 'innermost numbers in the center' and b)
the multiplication of the 'outermost numbers in the center'
4. Now for the resolution. I may be wrong but I
happen not to think that doing math from the left side is 'the more natural way'.
What I propose is simply put the 'right' and the 'left' numbers side by side by
respecting their right and left positions; once that is done, place underneath the two 'attached numbers' (that is placed side by side) exactly at the center position the 'innermost'
multiplication and then underneath, also at the center position the 'outermost'
multiplication (the order in which this is done does not matter). Then do the
addition and there you get the solution.
5. Note: when the multiplications yield single
digits add a zero in front of them. For instance 6*1 =6 and '6' would be placed
as '06'

Let us illustrate:

91*93

left is 81
Right is 03
Innermost center is 09
Outermost center is 27
Let us 'attach left and right' side by side; we obtain 8103
Then let us place 09 and 27 underneath the attached digits and do the addition
8103
09
27
----------
8463

Many thanks! You are great! If I am wrong or made a mistake please let me know!
L

[ODia]

____________ _________ _________ __
From: jfm1061 <jfm1061@yahoo. com>
To: wwbc@yahoogroups. com
Sent: Thursday, February 19, 2009 9:59:38 PM
Subject: [wwbc] Hidden Numbers

Math tricks are great for understanding the magic of math. But you
should be able to do math in a logical manner. I use a method of
math to train my mind for logic and pattern recognition. It is
the "hidden number" system. Most people should know the times tables
by heart. So for example, if you see 2*6 you will call out 12 without
much thought. Sadly, there are still many adults who are not able to
do simple mental math.

I have come up with a way to focus the mind on the simple parts and
discover the hidden parts of math. Start with pen and paper and work
your way up to mental math.

Look at this. 23*45. What are the obvious numbers? From left to
right, you can see 8 and 15. Because 2*4 is 8 and 3*5 is 15. What
you cannot see is the hidden number 22. The hidden number is the
secret to the entire problem. It brings the left and right side
numbers together. Learn to spot the hidden number and you will be
able to solve 2 by 2 multiplications with ease.

Look at the problem again. 23*45 = 8-22-15. Adding for the left
only the tens digits, 8 plus 2 is 10, attach the 2 in the ones
column. You have partial answer of 102. Add the 1 from 15 and attach
the 5 for the final answer 1035.

You will be doing math from the left side (the more natural may) and
when you have a single digit number next to a pair. YOU ONLY PLACE
IT ALONG SIDE. Practice with the following problems.

24*36 = Left 6, Hidden n 24, right 24. Add 6 + 2 = 8 and 4, add 2
to 4, attach the last 4.
89*47 = Left 32, Hidden n 92, right 63. 32-92-63. 32+9 =41+2, 412 +
6 is 418 attach 3.
56*47 = Left 20, Hidden n 59, right 42. Do it for yourself.
74*85 = Left 56, Hidden n 67, right ?
96*21 = Left 18, Hidden n ?, right ?

This is not a math trick, but a logical step in processing math.

24*36 = 864
89*47 = 4183
56*47 = 2632
74*85 = 6290
96*21 = 2016

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