Hello,

One more German book, but this time it is a translation of a title already
existing in English:

Alex Bellos' book "Alex's Adventures in Numberland" which contains a section
about Alex's impressions at the Mental Calculation World Cup 2008 in Leipzig is
now available in German language as well:

<http://www.amazon.de/exec/obidos/ASIN/3827008387/rekordklubsaxo03>

Ralf

Ralf, that is an excellent book!! ALex recently visited me in Tucson and
gave me a copy. It has photos of some of us included.
                                                      Jerry Newport



To: MentalCalculation@yahoogroups.com
From: info@...
Date: Sun, 2 Oct 2011 14:26:12 +0000
Subject: [Mental Calculation] "Alex's Adventures in Numberland" now in German




























       Hello,



One more German book, but this time it is a translation of a title already
existing in English:



Alex Bellos' book "Alex's Adventures in Numberland" which contains a section
about Alex's impressions at the Mental Calculation World Cup 2008 in Leipzig is
now available in German language as well:



<http://www.amazon.de/exec/obidos/ASIN/3827008387/rekordklubsaxo03>



Ralf


















[Non-text portions of this message have been removed]

On Sep 24 at the Speed Memory Championships in Rome
(http://www.speed-memory.com/Championships/Rome2011/rome2011.htm), I made the
same in 39.42 seconds. This is now the world record in the discipline p
(N=100,n=1,k=100).

At the same event Yusnier Viera set a new record in the discipline "365 dates of
the current year". He needed 2 min 50 sec (the old record was 3 min 10 sec).

There is now a website for pi-permutation where you can try your hand in this
matter yourself, and get a ranking: www.pi-sport.eu.



--- In MentalCalculation@yahoogroups.com, "mnempi" <voigt@...> wrote:
>
> In Renmin University, Beijing, I to-day made p (N=100,n=1,k=100), that is to
say the permutation of the first hundred digits of pi, in 41.14 s, surpassing my
old record from April this year (42.14 s) exactly by one second.
>

Hi All,

I posted a two-part essay on extracting 13th roots of 100-digit numbers
on my blog yesterday that some of you may find interesting. It starts at


http://myreckonings.com/wordpress/2011/10/05/the-13th-root-of-a-100-digi\
t-number-part-i/
<http://myreckonings.com/wordpress/2011/10/05/the-13th-root-of-a-100-dig\
it-number-part-i/>

The second part is linked at the end of the first part. A
printer-friendly PDF version of both parts combined is also linked at
the end of each part.

Part I is a historical overview of this task of mental calculation,
while Part II presents a new method for performing it.

My thanks to Willem Bouman for reading a draft version and correcting an
error of mine.

Cheers,

Ron Doerfler




[Non-text portions of this message have been removed]

You will find a general method of manually extracting any root of a given number
from my book ALTERNATIVE APPROACH TO MATHEMATICS VOL.I
 
This book is available for purchase either as ebook or hard paper bound copy
from http//i-proclaimbookstore.com.
 
There is also a manual method of raising a number with a decimal part to an
exponent with a decimal part from my book ALTERNATIVE APPROACH TO MATHEMATICS
VOL.II which is also available for purchase from I-Proclaim.
 
There are other technical books that I published with I-Proclaim which would be
very helpful in expanding ones ability in performing math operations and
extending ones awareness in Mathematics, Physics, Engineering, Astronomy and
Applied Science.


________________________________
From: rondrond1 <doerfpub@...>
To: MentalCalculation@yahoogroups.com
Sent: Saturday, October 8, 2011 11:43 AM
Subject: [Mental Calculation] New article on extracting 13th roots of 100-digit
numbers


 
Hi All,

I posted a two-part essay on extracting 13th roots of 100-digit numbers
on my blog yesterday that some of you may find interesting. It starts at

http://myreckonings.com/wordpress/2011/10/05/the-13th-root-of-a-100-digi\
t-number-part-i/
<http://myreckonings.com/wordpress/2011/10/05/the-13th-root-of-a-100-dig\
it-number-part-i/>

The second part is linked at the end of the first part. A
printer-friendly PDF version of both parts combined is also linked at
the end of each part.

Part I is a historical overview of this task of mental calculation,
while Part II presents a new method for performing it.

My thanks to Willem Bouman for reading a draft version and correcting an
error of mine.

Cheers,

Ron Doerfler

[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]

Dear Ron,

Thank you very much for this excellent article.

Ralf

--- In MentalCalculation@yahoogroups.com, "rondrond1" <doerfpub@...> wrote:
>
> Hi All,
>
> I posted a two-part essay on extracting 13th roots of 100-digit numbers
> on my blog yesterday that some of you may find interesting. It starts at
>
>
> http://myreckonings.com/wordpress/2011/10/05/the-13th-root-of-a-100-digi\
> t-number-part-i/
> <http://myreckonings.com/wordpress/2011/10/05/the-13th-root-of-a-100-dig\
> it-number-part-i/>
>
> The second part is linked at the end of the first part. A
> printer-friendly PDF version of both parts combined is also linked at
> the end of each part.
>
> Part I is a historical overview of this task of mental calculation,
> while Part II presents a new method for performing it.
>
> My thanks to Willem Bouman for reading a draft version and correcting an
> error of mine.
>
> Cheers,
>
> Ron Doerfler
>
>
>
>
> [Non-text portions of this message have been removed]
>

I look forward to reading this. Thanks to all who helped.
                                        Jerry Newport

To: MentalCalculation@yahoogroups.com
From: info@...
Date: Sat, 8 Oct 2011 15:13:59 +0000
Subject: [Mental Calculation] Re: New article on extracting 13th roots of
100-digit numbers




























       Dear Ron,



Thank you very much for this excellent article.



Ralf



--- In MentalCalculation@yahoogroups.com, "rondrond1" <doerfpub@...> wrote:

>

> Hi All,

>

> I posted a two-part essay on extracting 13th roots of 100-digit numbers

> on my blog yesterday that some of you may find interesting. It starts at

>

>

> http://myreckonings.com/wordpress/2011/10/05/the-13th-root-of-a-100-digi\

> t-number-part-i/

> <http://myreckonings.com/wordpress/2011/10/05/the-13th-root-of-a-100-dig\

> it-number-part-i/>

>

> The second part is linked at the end of the first part. A

> printer-friendly PDF version of both parts combined is also linked at

> the end of each part.

>

> Part I is a historical overview of this task of mental calculation,

> while Part II presents a new method for performing it.

>

> My thanks to Willem Bouman for reading a draft version and correcting an

> error of mine.

>

> Cheers,

>

> Ron Doerfler

>

>

>

>

> [Non-text portions of this message have been removed]

>


















[Non-text portions of this message have been removed]

Hi folks.
 
I've not seen any actviity here in the past few days, so I hope my membership
link has not been broken for whatever reason. Anyway: I am now on the lookout
for anyone who is interested in helping to set the question paper for the Mental
Calculations World Championship, to be held as part of the Mind Sports Olympiad
in London in August 2012. Jerry Newport has volunteeres his services, but has
specifically requested another person to help him in this regard. If anybody is
thinking they might be willing and able to help with this, please drop me a
line.
 
Best regards,
 
George

[Non-text portions of this message have been removed]

I am willing to work with Yusnier on this project.

                                 Jerry Newport





To: mentalcalculation@yahoogroups.com
From: george972453@...
Date: Thu, 20 Oct 2011 16:57:30 +0100
Subject: [Mental Calculation] MC World Championship 2012






Hi folks.

I've not seen any actviity here in the past few days, so I hope my membership
link has not been broken for whatever reason. Anyway: I am now on the lookout
for anyone who is interested in helping to set the question paper for the Mental
Calculations World Championship, to be held as part of the Mind Sports Olympiad
in London in August 2012. Jerry Newport has volunteeres his services, but has
specifically requested another person to help him in this regard. If anybody is
thinking they might be willing and able to help with this, please drop me a
line.

Best regards,

George

[Non-text portions of this message have been removed]






[Non-text portions of this message have been removed]

Welcome "jcvinet" to the Mental Calculation mailing list...
and congratulations!
You are the 2^10th member of the group!

Ralf

Dear fellow Calculators,

I just received from Ralf Laue Leipzig the message that my new worldrecord has
been recognised.
It concerns 10 integer divisions of 10 digit numbers divided by 5 digit numbers.
It took me 6 min 7.01 sec.
Much too long, in my feelings. Of course I was intensively in training, but what
stroke me it that gradually I got slower and made more mistakes.
The plan on the school where I was required that I firstly gave a guest lesson,
and after a short break my record attempt.
Undoubtedly this affected my work. So, in the future, if you are confronted with
this type of work: do not do anything before your attempt and only afterwards.

The referee and the timekeeper-both mathematicians-  saw that eg the first
questions were answered in 1 minute and that the rest took so much time. So
despite the random generator there is a difference in difficulty.

Now i take a short break and prepare for the German tournament for juveniles
where I'll meet Gert Mittring and Andy Robertshaw.

Best regards,

Willem Bouman





[Non-text portions of this message have been removed]

Willem, Congratulations on your new record.
                                                       Jerry Newport

To: MentalCalculation@yahoogroups.com
From: awap.bouman@...
Date: Sun, 23 Oct 2011 12:52:40 +0100
Subject: [Mental Calculation]




























       Dear fellow Calculators,



I just received from Ralf Laue Leipzig the message that my new worldrecord has
been recognised.

It concerns 10 integer divisions of 10 digit numbers divided by 5 digit numbers.
It took me 6 min 7.01 sec.

Much too long, in my feelings. Of course I was intensively in training, but what
stroke me it that gradually I got slower and made more mistakes.

The plan on the school where I was required that I firstly gave a guest lesson,
and after a short break my record attempt.

Undoubtedly this affected my work. So, in the future, if you are confronted with
this type of work: do not do anything before your attempt and only afterwards.



The referee and the timekeeper-both mathematicians-  saw that eg the first
questions were answered in 1 minute and that the rest took so much time. So
despite the random generator there is a difference in difficulty.



Now i take a short break and prepare for the German tournament for juveniles
where I'll meet Gert Mittring and Andy Robertshaw.



Best regards,



Willem Bouman



[Non-text portions of this message have been removed]


















[Non-text portions of this message have been removed]

Willem, about your new record, two questions. 1.  Since you were dividing
ten digit numbers by five digit numbers, I would assume that some of your
answers were six digit numbers?   2.  When you divide, do you look at the
endings of the numbers, the indices? It seems that speeds up the process.  In
any event, your new record is faster than you are giving yourself credit for!!

                                                  Jerry Newport

       PS:  For example, if I divide 48128 into 7243841536, looking at the
endings of 128 and 536 implies either an ending of 012 or 512 in the answer. The
leftmost digits of 48 and 7243 imply probably a 150 at the beginning and the
answer turns out to be 150512.
Much of the division work can be done by inspection without actually doing the
entire division.


--- In MentalCalculation@yahoogroups.com, "A.W.A.P. Bouman" <awap.bouman@...>
wrote:
>
> Dear fellow Calculators,
>
> I just received from Ralf Laue Leipzig the message that my new worldrecord has
been recognised.
> It concerns 10 integer divisions of 10 digit numbers divided by 5 digit
numbers. It took me 6 min 7.01 sec.
> Much too long, in my feelings. Of course I was intensively in training, but
what stroke me it that gradually I got slower and made more mistakes.
> The plan on the school where I was required that I firstly gave a guest
lesson, and after a short break my record attempt.
> Undoubtedly this affected my work. So, in the future, if you are confronted
with this type of work: do not do anything before your attempt and only
afterwards.
>
> The referee and the timekeeper-both mathematicians-  saw that eg the first
questions were answered in 1 minute and that the rest took so much time. So
despite the random generator there is a difference in difficulty.
>
> Now i take a short break and prepare for the German tournament for juveniles
where I'll meet Gert Mittring and Andy Robertshaw.
>
> Best regards,
>
> Willem Bouman
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

Willem, after my last post, it occurred to me that I had not listed all of
the possible endings in my example... 137, 262,387, 637, 762 and 887 also would
produce an ending of 536 if multiplied by a number ending in 128. My main
curiosity is in whether you do the complete divisions or use something similar
to the manner of inspection I suggested. Thanks for your attention and
congratulations again on your new world record!!
                                                                     Jerry
Newport

To: MentalCalculation@yahoogroups.com
From: wholphin48@...
Date: Sun, 23 Oct 2011 18:46:47 +0000
Subject: [Mental Calculation] Question for new world record holder, WIllem
Bouman....






























       Willem, about your new record, two questions. 1.  Since you were dividing
ten digit numbers by five digit numbers, I would assume that some of your
answers were six digit numbers?   2.  When you divide, do you look at the
endings of the numbers, the indices? It seems that speeds up the process.  In
any event, your new record is faster than you are giving yourself credit for!!



Jerry Newport



PS:  For example, if I divide 48128 into 7243841536, looking at the endings of
128 and 536 implies either an ending of 012 or 512 in the answer. The leftmost
digits of 48 and 7243 imply probably a 150 at the beginning and the answer turns
out to be 150512.

Much of the division work can be done by inspection without actually doing the
entire division.



--- In MentalCalculation@yahoogroups.com, "A.W.A.P. Bouman" <awap.bouman@...>
wrote:

>

> Dear fellow Calculators,

>

> I just received from Ralf Laue Leipzig the message that my new worldrecord has
been recognised.

> It concerns 10 integer divisions of 10 digit numbers divided by 5 digit
numbers. It took me 6 min 7.01 sec.

> Much too long, in my feelings. Of course I was intensively in training, but
what stroke me it that gradually I got slower and made more mistakes.

> The plan on the school where I was required that I firstly gave a guest
lesson, and after a short break my record attempt.

> Undoubtedly this affected my work. So, in the future, if you are confronted
with this type of work: do not do anything before your attempt and only
afterwards.

>

> The referee and the timekeeper-both mathematicians-  saw that eg the first
questions were answered in 1 minute and that the rest took so much time. So
despite the random generator there is a difference in difficulty.

>

> Now i take a short break and prepare for the German tournament for juveniles
where I'll meet Gert Mittring and Andy Robertshaw.

>

> Best regards,

>

> Willem Bouman

>

>

>

>

>

> [Non-text portions of this message have been removed]

>


















[Non-text portions of this message have been removed]

Hi folks.
 
Willem, serious congratulations are in order. You say you took much too long?
Not a word of it! A world record is a wonderful achievement. Well done my
friend!
 
You're probably right about going into the exercise fresh; I know that the
public displays put on by the contestants at the Mental Calculations World Cup
are only performed after the contest itself has been completed.
 
As for the junior tournament, I was looking forward to observing the techniques
and results but unfortunately I am unable to attend personally. I am sure the
youngsters will have some surprises ready for those of us who have gathered a
few more years than they have.
 
Best regards,
 
George

--- On Sun, 23/10/11, A.W.A.P. Bouman <awap.bouman@...> wrote:


From: A.W.A.P. Bouman <awap.bouman@...>
Subject: [Mental Calculation]
To: "mental calculation" <MentalCalculation@yahoogroups.com>
Date: Sunday, 23 October, 2011, 12:52



 



Dear fellow Calculators,

I just received from Ralf Laue Leipzig the message that my new worldrecord has
been recognised.
It concerns 10 integer divisions of 10 digit numbers divided by 5 digit numbers.
It took me 6 min 7.01 sec.
Much too long, in my feelings. Of course I was intensively in training, but what
stroke me it that gradually I got slower and made more mistakes.
The plan on the school where I was required that I firstly gave a guest lesson,
and after a short break my record attempt.
Undoubtedly this affected my work. So, in the future, if you are confronted with
this type of work: do not do anything before your attempt and only afterwards.

The referee and the timekeeper-both mathematicians- saw that eg the first
questions were answered in 1 minute and that the rest took so much time. So
despite the random generator there is a difference in difficulty.

Now i take a short break and prepare for the German tournament for juveniles
where I'll meet Gert Mittring and Andy Robertshaw.

Best regards,

Willem Bouman

[Non-text portions of this message have been removed]








[Non-text portions of this message have been removed]

Hi folks.
 
When dividing by an odd number ending other than with a '5', or when dividing by
a number with a single factor of 2, speed of division can indeed be enhanced by
creating the solution from both ends at once. Willem is an expert in
calculations, especially in division; I would not expect such a matter to go
unnoticed by such a man.
 
Best regards,
 
George

--- On Mon, 24/10/11, Gerald Newport <wholphin48@...> wrote:


From: Gerald Newport <wholphin48@...>
Subject: RE: [Mental Calculation] Question for new world record holder, WIllem
Bouman....
To: "Mentalmath List" <mentalcalculation@yahoogroups.com>
Date: Monday, 24 October, 2011, 0:13



 





Willem, after my last post, it occurred to me that I had not listed all of the
possible endings in my example... 137, 262,387, 637, 762 and 887 also would
produce an ending of 536 if multiplied by a number ending in 128. My main
curiosity is in whether you do the complete divisions or use something similar
to the manner of inspection I suggested. Thanks for your attention and
congratulations again on your new world record!!
Jerry Newport

To: MentalCalculation@yahoogroups.com
From: wholphin48@...
Date: Sun, 23 Oct 2011 18:46:47 +0000
Subject: [Mental Calculation] Question for new world record holder, WIllem
Bouman....

Willem, about your new record, two questions. 1. Since you were dividing ten
digit numbers by five digit numbers, I would assume that some of your answers
were six digit numbers? 2. When you divide, do you look at the endings of the
numbers, the indices? It seems that speeds up the process. In any event, your
new record is faster than you are giving yourself credit for!!

Jerry Newport

PS: For example, if I divide 48128 into 7243841536, looking at the endings of
128 and 536 implies either an ending of 012 or 512 in the answer. The leftmost
digits of 48 and 7243 imply probably a 150 at the beginning and the answer turns
out to be 150512.

Much of the division work can be done by inspection without actually doing the
entire division.

--- In MentalCalculation@yahoogroups.com, "A.W.A.P. Bouman" <awap.bouman@...>
wrote:

>

> Dear fellow Calculators,

>

> I just received from Ralf Laue Leipzig the message that my new worldrecord has
been recognised.

> It concerns 10 integer divisions of 10 digit numbers divided by 5 digit
numbers. It took me 6 min 7.01 sec.

> Much too long, in my feelings. Of course I was intensively in training, but
what stroke me it that gradually I got slower and made more mistakes.

> The plan on the school where I was required that I firstly gave a guest
lesson, and after a short break my record attempt.

> Undoubtedly this affected my work. So, in the future, if you are confronted
with this type of work: do not do anything before your attempt and only
afterwards.

>

> The referee and the timekeeper-both mathematicians- saw that eg the first
questions were answered in 1 minute and that the rest took so much time. So
despite the random generator there is a difference in difficulty.

>

> Now i take a short break and prepare for the German tournament for juveniles
where I'll meet Gert Mittring and Andy Robertshaw.

>

> Best regards,

>

> Willem Bouman

>

>

>

>

>

> [Non-text portions of this message have been removed]

>



[Non-text portions of this message have been removed]








[Non-text portions of this message have been removed]

Dear fellow calculators,

Hereunder you'll find my answer to Jerry Newport, as a reaction on the remarks
of George Lane.

Of course there is more to be said.
If there is need for a more extensive eludication, I could do this after the
tournament in Germany. It will certainly take some time, so no hurry please,
if...

Best regards,

Willem Bouman




----- Oorspronkelijk bericht -----
Van: A.W.A.P. Bouman
Aan: Newport, Gerald
Verzonden: maandag 24 oktober 2011 13:00
Onderwerp: GN 11-10-24


Good afternoon Jerry,


The program used gave only 10/5/5 numbers. I have no idea how this works, for
indeed, in principle a 10 digit number divided by a 5 digit one can give a five
or six digit answer, no other possibilities.

It stroke the referees that some answers were given at lightning speed and other
questions appeared to be very tough.
You had the right feeling.
Eg when the divisor is in a confident environment the last two or three digits
are easily to be found.
For all neutrality I take some examples out of my training questions.

1088155099÷44021. The 24 are simply to be found, and 099 ÷21 is 719, that's very
clear.
Or:
2925835347÷60043. Here the 5347÷43 can quickly give 729.

In fact one can also think the dividend has 2^6 and the divider has 2^3, so the
answer has to have 2^3, but this does not speed up the operation.

There are two factors which increase the difficulty of a question: the more
powers of two and the more present fives. Both are very tricky.

I hope having answered your questions sufficiently.
If unexpectedly not, drop me a line.

Best regards,

Willem

[Non-text portions of this message have been removed]

Willem, it sounds like we have similar thinking on division. Thanks for
your response.

I had my computer generate some problems similar to what you must have solved
and your time holds up quite well.

                                           Jerry Newport

--- In MentalCalculation@yahoogroups.com, "A.W.A.P. Bouman" <awap.bouman@...>
wrote:
>
> Dear fellow calculators,
>
> Hereunder you'll find my answer to Jerry Newport, as a reaction on the remarks
of George Lane.
>
> Of course there is more to be said.
> If there is need for a more extensive eludication, I could do this after the
tournament in Germany. It will certainly take some time, so no hurry please,
if...
>
> Best regards,
>
> Willem Bouman
>
>
>
>
> ----- Oorspronkelijk bericht -----
> Van: A.W.A.P. Bouman
> Aan: Newport, Gerald
> Verzonden: maandag 24 oktober 2011 13:00
> Onderwerp: GN 11-10-24
>
>
> Good afternoon Jerry,
>
>
> The program used gave only 10/5/5 numbers. I have no idea how this works, for
indeed, in principle a 10 digit number divided by a 5 digit one can give a five
or six digit answer, no other possibilities.
>
> It stroke the referees that some answers were given at lightning speed and
other questions appeared to be very tough.
> You had the right feeling.
> Eg when the divisor is in a confident environment the last two or three digits
are easily to be found.
> For all neutrality I take some examples out of my training questions.
>
> 1088155099÷44021. The 24 are simply to be found, and 099 ÷21 is 719, that's
very clear.
> Or:
> 2925835347÷60043. Here the 5347÷43 can quickly give 729.
>
> In fact one can also think the dividend has 2^6 and the divider has 2^3, so
the answer has to have 2^3, but this does not speed up the operation.
>
> There are two factors which increase the difficulty of a question: the more
powers of two and the more present fives. Both are very tricky.
>
> I hope having answered your questions sufficiently.
> If unexpectedly not, drop me a line.
>
> Best regards,
>
> Willem
>
> [Non-text portions of this message have been removed]
>

Hello,

a few words about the rules:
Two five-digit numbers A and B whose product P has 10 digits are selected at
random.
The task P / A is presented, the calculator has to write down B.

You can download two programs for generating random tasks:

a) (You need to have a Java Runtime Enviroment installed)
Download
http://www.recordholders.org/downloads/division.class

Start it by executing
java division

The program writes tasks and solutions to the console.
Please separate the solutions (last column) from the tasks.

Note: The source for the program can be found at:
http://www.recordholders.org/downloads/division.java

b) (You need to have MS Excel with the option "support macro execution"
installed)
Download
http://www.recordholders.org/downloads/division.xls

Open the file using MS Excel. Say "yes" when being asked whether you want to
allow the execution of macros.

Generate two files (one for the tasks and one for the solutions) by pressing
CTRL + d

Wish you a lot of fun doing divisions,
Ralf

--- In MentalCalculation@yahoogroups.com, "Jerry" <wholphin48@...> wrote:
>
>
>       Willem, about your new record, two questions. 1.  Since you were
dividing ten digit numbers by five digit numbers, I would assume that some of
your answers were six digit numbers?

Hi guys,
 
The process of creating a ten-over-five integer division with a five digit
result can be created in a number of ways; Within my 'Pegasus' training file on
Microsoft Excel, I have a similar process (using smaller numbers) in the Integer
Brackets section. It works like this:
 
First column: Set a random integer number within a set range, perhaps between
10,000 and 99,999.
 
Second column: Set a random integer number within a set range, perhaps between
10^9 and (10^10-1).
 
Third column: Determine the result of division of the second column by the
first, and take the integer part of this.
 
Fourth column: Set a random integer number within a set range, perhaps between
1,000 and 9,999.
 
Fifth column: If third column is over 9,999 in value, take third column,
otherwise take third column plus fourth column.
 
Sixth column: Multiply first column by fifth column.
 
The problem can now take the sixth column as a reference for the parent number,
with the first and the fifth as the divisor and the result (in either order).

Best regards,
 
George

--- On Mon, 24/10/11, A.W.A.P. Bouman <awap.bouman@...> wrote:


From: A.W.A.P. Bouman <awap.bouman@...>
Subject: [Mental Calculation] Fw: GN 11-10-24
To: "mental calculation" <MentalCalculation@yahoogroups.com>
Date: Monday, 24 October, 2011, 15:58



 



Dear fellow calculators,

Hereunder you'll find my answer to Jerry Newport, as a reaction on the remarks
of George Lane.

Of course there is more to be said.
If there is need for a more extensive eludication, I could do this after the
tournament in Germany. It will certainly take some time, so no hurry please,
if...

Best regards,

Willem Bouman

----- Oorspronkelijk bericht -----
Van: A.W.A.P. Bouman
Aan: Newport, Gerald
Verzonden: maandag 24 oktober 2011 13:00
Onderwerp: GN 11-10-24

Good afternoon Jerry,

The program used gave only 10/5/5 numbers. I have no idea how this works, for
indeed, in principle a 10 digit number divided by a 5 digit one can give a five
or six digit answer, no other possibilities.

It stroke the referees that some answers were given at lightning speed and other
questions appeared to be very tough.
You had the right feeling.
Eg when the divisor is in a confident environment the last two or three digits
are easily to be found.
For all neutrality I take some examples out of my training questions.

1088155099÷44021. The 24 are simply to be found, and 099 ÷21 is 719, that's
very clear.
Or:
2925835347÷60043. Here the 5347÷43 can quickly give 729.

In fact one can also think the dividend has 2^6 and the divider has 2^3, so the
answer has to have 2^3, but this does not speed up the operation.

There are two factors which increase the difficulty of a question: the more
powers of two and the more present fives. Both are very tricky.

I hope having answered your questions sufficiently.
If unexpectedly not, drop me a line.

Best regards,

Willem

[Non-text portions of this message have been removed]








[Non-text portions of this message have been removed]

Kiyrah, It is a fun group. I looked for your name in the event I went to
Germany in 2010. Perhaps you know me from some other event? I will be at the
MMWC event in 2012.
                                                                      Jerry
Newport   Tucson, AZ

To: MentalCalculation@yahoogroups.com
From: kiyrahkeith@...
Date: Fri, 23 Sep 2011 10:01:57 -0700
Subject: Re: [Mental Calculation] fun way to practice factoring....




























       I didn't know you were on there too! I got a membership not to long a go
and would have looked on there but school has got me pretty busy. It is a really
fun group.



Kiyrah



--- On Wed, 9/21/11, Jerry <wholphin48@...> wrote:



From: Jerry <wholphin48@...>

Subject: [Mental Calculation] fun way to practice factoring....

To: MentalCalculation@yahoogroups.com

Date: Wednesday, September 21, 2011, 1:16 PM







Whenever I see a four or five digit number and have the time, I try to factor
that number and the next nineteen numbers. I call such a sequence a "run." Of
course, usually there will be a prime or more in there. In that case, I just
factor additional numbers until I have done twenty.  It is fun and seems easier
than doing twenty random numbers since you know that in such a sequence, every
other number is even, every third number has three as a factor etc. WIth random
numbers, you are out in the cold with every number!



It works for me. I have done some four digit "runs" in less than a minute. They
are much easier than the five digit number runs which usually take 3-5 minutes.
On the average, it seems to take me about 2-4 times as long to do the five digit
runs.



Jerry Newport



[Non-text portions of this message have been removed]


















[Non-text portions of this message have been removed]

My proposal is to have a record for factoring ten six digit numbers.
Does anyone have a program that can generate such sets?  There also is no record
for factoring four digit numbers but in that case, I think twenty is a
reasonable number to factor as that is what was required for WIllem Bouman who
holds the record for five digit numbers.

       Perhaps there is room for the four digit record too. Below that, it seems
too trivial to consider. Many of us, I guess, would need no time at all to
factor a group of three digit numbers.

                                                Jerry Newport

Hi Jerry,
 
My Pegasus file (on Microsoft Excel) can produce prime factors problems within
set templates, and I could easily set up a page which generates sets of
five-digit numbers to be worked upon. Would you like me to e-mail you such a
page? Perhaps a small workbook file with sepparate pages of individual number
lengths, such as 4, 5, and 6? Just a thought...
 
Best regards,
 
George

--- On Thu, 27/10/11, Jerry <wholphin48@...> wrote:


From: Jerry <wholphin48@...>
Subject: [Mental Calculation] Query: Possible world record for factoring six
digit numbers....
To: MentalCalculation@yahoogroups.com
Date: Thursday, 27 October, 2011, 17:16



 





My proposal is to have a record for factoring ten six digit numbers. Does anyone
have a program that can generate such sets? There also is no record for
factoring four digit numbers but in that case, I think twenty is a reasonable
number to factor as that is what was required for WIllem Bouman who holds the
record for five digit numbers.

Perhaps there is room for the four digit record too. Below that, it seems too
trivial to consider. Many of us, I guess, would need no time at all to factor a
group of three digit numbers.

Jerry Newport








[Non-text portions of this message have been removed]

George, that sounds like a lot of fun!!  I have not gone after the five
digit record because at present, the time, 13:39 translates to my birthday if
converted to seconds: 13:39 = 819 and my birthday is 8-19. Thanks for the offer.
                                                             Jerry Newport

To: MentalCalculation@yahoogroups.com
From: george972453@...
Date: Sat, 29 Oct 2011 12:58:30 +0100
Subject: Re: [Mental Calculation] Query:  Possible world record for factoring
six digit numbers....




























       Hi Jerry,



My Pegasus file (on Microsoft Excel) can produce prime factors problems within
set templates, and I could easily set up a page which generates sets of
five-digit numbers to be worked upon. Would you like me to e-mail you such a
page? Perhaps a small workbook file with sepparate pages of individual number
lengths, such as 4, 5, and 6? Just a thought...



Best regards,



George



--- On Thu, 27/10/11, Jerry <wholphin48@...> wrote:



From: Jerry <wholphin48@...>

Subject: [Mental Calculation] Query: Possible world record for factoring six
digit numbers....

To: MentalCalculation@yahoogroups.com

Date: Thursday, 27 October, 2011, 17:16







My proposal is to have a record for factoring ten six digit numbers. Does anyone
have a program that can generate such sets? There also is no record for
factoring four digit numbers but in that case, I think twenty is a reasonable
number to factor as that is what was required for WIllem Bouman who holds the
record for five digit numbers.



Perhaps there is room for the four digit record too. Below that, it seems too
trivial to consider. Many of us, I guess, would need no time at all to factor a
group of three digit numbers.



Jerry Newport



[Non-text portions of this message have been removed]


















[Non-text portions of this message have been removed]

Hi there!
 
I've decided to redesign the way I set u m prime factors problems, so that I can
get a wider range of factors as well as ensuring I get the right length of
number every time (without it beign prime). I'm well on the way, but it might be
another day or two before it's finished - and it will be set to give groups of
problems ranging from four to twelve digits in length.
 
Anybody else interested, while I'm at it?
 
Best regards,
 
George

--- On Sat, 29/10/11, Gerald Newport <wholphin48@...> wrote:


From: Gerald Newport <wholphin48@...>
Subject: RE: [Mental Calculation] Query: Possible world record for factoring six
digit numbers....
To: "Mentalmath List" <mentalcalculation@yahoogroups.com>
Date: Saturday, 29 October, 2011, 22:50



 





George, that sounds like a lot of fun!! I have not gone after the five digit
record because at present, the time, 13:39 translates to my birthday if
converted to seconds: 13:39 = 819 and my birthday is 8-19. Thanks for the offer.
Jerry Newport

To: MentalCalculation@yahoogroups.com
From: george972453@...
Date: Sat, 29 Oct 2011 12:58:30 +0100
Subject: Re: [Mental Calculation] Query: Possible world record for factoring six
digit numbers....

Hi Jerry,

My Pegasus file (on Microsoft Excel) can produce prime factors problems within
set templates, and I could easily set up a page which generates sets of
five-digit numbers to be worked upon. Would you like me to e-mail you such a
page? Perhaps a small workbook file with sepparate pages of individual number
lengths, such as 4, 5, and 6? Just a thought...

Best regards,

George

--- On Thu, 27/10/11, Jerry <wholphin48@...> wrote:

From: Jerry <wholphin48@...>

Subject: [Mental Calculation] Query: Possible world record for factoring six
digit numbers....

To: MentalCalculation@yahoogroups.com

Date: Thursday, 27 October, 2011, 17:16

My proposal is to have a record for factoring ten six digit numbers. Does anyone
have a program that can generate such sets? There also is no record for
factoring four digit numbers but in that case, I think twenty is a reasonable
number to factor as that is what was required for WIllem Bouman who holds the
record for five digit numbers.

Perhaps there is room for the four digit record too. Below that, it seems too
trivial to consider. Many of us, I guess, would need no time at all to factor a
group of three digit numbers.

Jerry Newport

[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]








[Non-text portions of this message have been removed]

George, I will definitely be interested. Just tied up a couple of days,
cleaning up my former residence and unpacking in my new place but I will be back
to playtime come wednesday!!  Thanks in advance for your efforts.
                                                            Jerry Newport

To: MentalCalculation@yahoogroups.com
From: george972453@...
Date: Mon, 31 Oct 2011 18:15:20 +0000
Subject: RE: [Mental Calculation] Query:  Possible world record for factoring
six digit numbers....




























       Hi there!



I've decided to redesign the way I set u m prime factors problems, so that I can
get a wider range of factors as well as ensuring I get the right length of
number every time (without it beign prime). I'm well on the way, but it might be
another day or two before it's finished - and it will be set to give groups of
problems ranging from four to twelve digits in length.



Anybody else interested, while I'm at it?



Best regards,



George



--- On Sat, 29/10/11, Gerald Newport <wholphin48@...> wrote:



From: Gerald Newport <wholphin48@...>

Subject: RE: [Mental Calculation] Query: Possible world record for factoring six
digit numbers....

To: "Mentalmath List" <mentalcalculation@yahoogroups.com>

Date: Saturday, 29 October, 2011, 22:50







George, that sounds like a lot of fun!! I have not gone after the five digit
record because at present, the time, 13:39 translates to my birthday if
converted to seconds: 13:39 = 819 and my birthday is 8-19. Thanks for the offer.

Jerry Newport



To: MentalCalculation@yahoogroups.com

From: george972453@...

Date: Sat, 29 Oct 2011 12:58:30 +0100

Subject: Re: [Mental Calculation] Query: Possible world record for factoring six
digit numbers....



Hi Jerry,



My Pegasus file (on Microsoft Excel) can produce prime factors problems within
set templates, and I could easily set up a page which generates sets of
five-digit numbers to be worked upon. Would you like me to e-mail you such a
page? Perhaps a small workbook file with sepparate pages of individual number
lengths, such as 4, 5, and 6? Just a thought...



Best regards,



George



--- On Thu, 27/10/11, Jerry <wholphin48@...> wrote:



From: Jerry <wholphin48@...>



Subject: [Mental Calculation] Query: Possible world record for factoring six
digit numbers....



To: MentalCalculation@yahoogroups.com



Date: Thursday, 27 October, 2011, 17:16



My proposal is to have a record for factoring ten six digit numbers. Does anyone
have a program that can generate such sets? There also is no record for
factoring four digit numbers but in that case, I think twenty is a reasonable
number to factor as that is what was required for WIllem Bouman who holds the
record for five digit numbers.



Perhaps there is room for the four digit record too. Below that, it seems too
trivial to consider. Many of us, I guess, would need no time at all to factor a
group of three digit numbers.



Jerry Newport



[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]


















[Non-text portions of this message have been removed]

Good morning Jerry,

I just returned from Münster, where was the national championship MC for the
younger children froim 9-16 years.
Jan van Koningsveld, Gert Mittring and I gave some workshops, it was really
great.

Factorisation: after deliberation with Ralf the decision was taken not to do
factorisation of 4 digit numbers. Memory specialists could learn all the primes
till 10.00 being 1219 by heart which would reduce the worthiness of the record,
and so came out 5 digits.

6 Digits is very very ambitious. I'll ask Ralf to create a test set, which Ralf
could send to you and copy to me.

You eg get 658389 which is definetly not simple. And surely a set of 10 numbers
would be a heavy task.

But: really a challenge!

Best regards,

Willem




   ----- Oorspronkelijk bericht -----
   Van: Jerry
   Aan: MentalCalculation@yahoogroups.com
   Verzonden: donderdag 27 oktober 2011 17:16
   Onderwerp: [Mental Calculation] Query: Possible world record for factoring six
digit numbers....





   My proposal is to have a record for factoring ten six digit numbers. Does
anyone have a program that can generate such sets? There also is no record for
factoring four digit numbers but in that case, I think twenty is a reasonable
number to factor as that is what was required for WIllem Bouman who holds the
record for five digit numbers.

   Perhaps there is room for the four digit record too. Below that, it seems too
trivial to consider. Many of us, I guess, would need no time at all to factor a
group of three digit numbers.

   Jerry Newport





[Non-text portions of this message have been removed]

Ralf, I have to agree that four digits is not suitable for a record. It
is fun to do a bunch of them for demonstrations but Daniel Tammett, for one,
knows all of the primes below ten thousand. He sees them as different colors!!
Daniel is an autistic savant who lives in England and has written some
interesting books about his synesthesia, a condition in which senses cross each
other. He sees numbers as different colors and memorized over 22 thousand digits
of Pi.
        I guess I will have to go after six digits or throw in the towel if
nobody else changes the five digit record and go after that. I am in no hurry as
my health is good and expect to be around a couple of more decades! Thanks for
your feedback.
                                                       Jerry Newport
     PS:  i have sent a copy of this to Ralf too.

To: MentalCalculation@yahoogroups.com
From: awap.bouman@...
Date: Wed, 2 Nov 2011 10:37:14 +0100
Subject: Re: [Mental Calculation] Query:  Possible world record for factoring
six digit numbers....




























       Good morning Jerry,



I just returned from Münster, where was the national championship MC for the
younger children froim 9-16 years.

Jan van Koningsveld, Gert Mittring and I gave some workshops, it was really
great.



Factorisation: after deliberation with Ralf the decision was taken not to do
factorisation of 4 digit numbers. Memory specialists could learn all the primes
till 10.00 being 1219 by heart which would reduce the worthiness of the record,
and so came out 5 digits.



6 Digits is very very ambitious. I'll ask Ralf to create a test set, which Ralf
could send to you and copy to me.



You eg get 658389 which is definetly not simple. And surely a set of 10 numbers
would be a heavy task.



But: really a challenge!



Best regards,



Willem



----- Oorspronkelijk bericht -----

   Van: Jerry

   Aan: MentalCalculation@yahoogroups.com

   Verzonden: donderdag 27 oktober 2011 17:16

   Onderwerp: [Mental Calculation] Query: Possible world record for factoring six
digit numbers....



My proposal is to have a record for factoring ten six digit numbers. Does anyone
have a program that can generate such sets? There also is no record for
factoring four digit numbers but in that case, I think twenty is a reasonable
number to factor as that is what was required for WIllem Bouman who holds the
record for five digit numbers.



Perhaps there is room for the four digit record too. Below that, it seems too
trivial to consider. Many of us, I guess, would need no time at all to factor a
group of three digit numbers.



Jerry Newport



[Non-text portions of this message have been removed]


















[Non-text portions of this message have been removed]

Hi George!
 
I may be able to help on this as there are several questions in math that I like
others to try solving. FYI I am the author of two books in ALTERNATIVE APPROACH
TO MATHEMATICS and a questions and answers book entitled DRACO'S ANSWERS IN
MATHEMATICS. These books are published with I-Proclaim Press in the USA and are
now available for purchase at http//i-proclaimbookstore.com either as ebooks or
hard paper bound copies.
 
Just let me know when you want the questions turned in.
 
Regards,
Dio


________________________________
From: George Lane <george972453@...>
To: Mental Calculations <mentalcalculation@yahoogroups.com>
Sent: Thursday, October 20, 2011 11:57 PM
Subject: [Mental Calculation] MC World Championship 2012


 
Hi folks.
 
I've not seen any actviity here in the past few days, so I hope my membership
link has not been broken for whatever reason. Anyway: I am now on the lookout
for anyone who is interested in helping to set the question paper for the Mental
Calculations World Championship, to be held as part of the Mind Sports Olympiad
in London in August 2012. Jerry Newport has volunteeres his services, but has
specifically requested another person to help him in this regard. If anybody is
thinking they might be willing and able to help with this, please drop me a
line.
 
Best regards,
 
George

[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]

Hi Dio,
 
Many thanks for your offer of assistance, it certainly looks as though you would
have some interesting and valuable input to give.
 
I will put your name forward to the chief organiser, Etan Ilfeld, but I am not
sure if he wil want to accept further people onto the production team. I have in
fact already advised another contributor that we would probably not require his
assistanec as such; however he stated that he would not be certain of his
availability until shortly before the target date for the completion of the test
paper (May 1st).
 
Overall, I must apologise to the group for not notifying sooner that we now have
sufficient members on the production team. However, in the light of this
failing, and in view of the new 'slant' of input you (Dio) can provide, I shall
- as I have said above - put your name forward to Etan with much thanks.
 
Best regards to all,
 
George

--- On Fri, 21/10/11, Diosdado |Fragata <dadofragata@...> wrote:


From: Diosdado |Fragata <dadofragata@...>
Subject: Re: [Mental Calculation] MC World Championship 2012
To: "MentalCalculation@yahoogroups.com" <MentalCalculation@yahoogroups.com>
Date: Friday, 21 October, 2011, 1:26



 



Hi George!
 
I may be able to help on this as there are several questions in math that I like
others to try solving. FYI I am the author of two books in ALTERNATIVE APPROACH
TO MATHEMATICS and a questions and answers book entitled DRACO'S ANSWERS IN
MATHEMATICS. These books are published with I-Proclaim Press in the USA and are
now available for purchase at http//i-proclaimbookstore.com either as ebooks or
hard paper bound copies.
 
Just let me know when you want the questions turned in.
 
Regards,
Dio

________________________________
From: George Lane <george972453@...>
To: Mental Calculations <mentalcalculation@yahoogroups.com>
Sent: Thursday, October 20, 2011 11:57 PM
Subject: [Mental Calculation] MC World Championship 2012

 
Hi folks.
 
I've not seen any actviity here in the past few days, so I hope my membership
link has not been broken for whatever reason. Anyway: I am now on the lookout
for anyone who is interested in helping to set the question paper for the Mental
Calculations World Championship, to be held as part of the Mind Sports Olympiad
in London in August 2012. Jerry Newport has volunteeres his services, but has
specifically requested another person to help him in this regard. If anybody is
thinking they might be willing and able to help with this, please drop me a
line.
 
Best regards,
 
George

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]








[Non-text portions of this message have been removed]