5112

Mental Calculation World Cup 2014 registration period ends in 68 day
Hello, This is just a reminder that the registration for MCWC 2014 is open. You will help with the organization if you do not wait until the very last moment

Ralf Laue

Mar 25

#5112
5111

Re: New training files
Hi George, first of all, I'd like to congratulate you for your effort and dedication. I've been looking for some material or any methodology that may support

JOSE CARLOS-BAPTISTA

Mar 24

#5111
5110

Re: Mental Calculation World Cup 2014 Announcement
Hello, The short answer is: Everyone can request a special format for each task, including task 5. The request should be sent by e-mail until 1 July. Ralf

ralf_laue

Mar 6

#5110Fetching Sponsored Content...

5109

Re: Mental Calculation World Cup 2014 Announcement
Dear Ralf and everyone, Thanks a lot for letting us know about the MCWC-2014 (city, venue and the new task) . I have a question. In the update Rules

nodden_1984_mes_gr

Mar 6

#5109
5108

Mental Calculation World Cup 2014 Announcement
- Please help to circulate this call for registrations - Mental calculators from all over the world are invited to the 6th Mental Calculation World Cup 2014!

Ralf Laue

Mar 5

#5108
5107

Re: New training files
Hi George, That's a great feat! It will be splendid if you can send us a copy of your great work! Thanks in advance. Warmest regards, Edwin & kids

Edwin Tapang

Mar 1

#5107
5106

Re: New training files
Hi George, I would love to have the workbook! Indeed, If Willem uses his dropbox account, I would love to have a link. Cheers, Kinma.

kinma216

Feb 23

#5106
5105

Re: New training files
Hi George, Fortunately I have a dropbox account, so if you mail me the code I need, I can open your file and save it. Did you already book your flight: if you

A.W.A.P. Bouman

Feb 22

#5105
5104

Re: New training files
Hi George I would like to have a copy by mail Thanks about your great work and effort From: MentalCalculation@yahoogroups.com

Adi Tamir

Feb 22

#5104
5103

Re: New training files
Hi George, Could I get a copy please? Thanks a lot! Chris To: mentalcalculation@yahoogroups.com From: george972453@... Date: Fri, 21 Feb 2014 16:49:17

Simba .

Feb 21

#5103
5102

New training files
Good morning/afternoon/evening to everyone; A few days ago, I completed the testing of the latest version of my Pegasus mental calculations training

George Lane

Feb 21

#5102
5101

Re: square root
Ty very much Ron From: MentalCalculation@yahoogroups.com [mailto:MentalCalculation@yahoogroups.com] On Behalf Of doerfpub@... Sent: Sunday,

Adi Tamir

Feb 16

#5101
5100

Re: square root
Hi Adi, As you probably already know, a better square root r' of a number N can be found from an initial root r by averaging r and N/r^2: r' = (r + N/r^2) /

rondrond1

Feb 15

#5100
5099

square root
. suppose I know that the square root of 458789 for example begins in : 677.3 what is the fastest way to calculate mentally the next digit? I will

Adi Tamir

Feb 15

#5099
5098

Re: Decimal numbers to Decimal powers, via Logs
I love to do these calculations! They are easy to do using logs as Nodas showed. However, to keep my mind sharp, I like to do them also using different ways.

kinma216

Feb 15

#5098Fetching Sponsored Content...

5097

Re: Decimal numbers to Decimal powers, via Logs
Hi All, Perhaps my two papers, "The Practical Use of the Bemer Method for Exponentials" "Fast Approximation of the Tangent, Hyperbolic Tangent, Exponential and

rondrond1

Feb 6

#5097
5096

Re: Decimal numbers to Decimal powers, via Logs
Hi Steven and everyone, For mentally doing 2.2 ^ 8.3, I would take the logarithm of it. Then, simplify to a single number of 5-digit accuracy and finally seek

nodden_1984_mes_gr

Feb 6

#5096
5095

Decimal numbers to Decimal powers, via Logs
Hi all, Has anyone here been able to mentally raise decimal numbers to decimal powers? I have mentally done 2.2^8.3 = 695, using a table of Prememorized Common

webcash56

Feb 3

#5095
5094

Re: 531, 7531 and so on are not primes, why??
If we turn the numbers around: 13 135791113151719 125791113151719212325272931 125791113151719212325272931333537394143454749515355575961636567

retothejuggler

Dec 18, 2013

#5094
5093

Re: 531, 7531 and so on are not primes, why??
Next we have 12312111911711511311110910710510310199979593918987858381797775737169676563615957555351494745434139373533312927252321191715131197531 Compared with

retothejuggler

Dec 14, 2013

#5093
5092

Re: 531, 7531 and so on are not primes, why??
Hello Chris Awesome, thanks!- It`s a very funny sequence. A juggler`s Mersenne? :-))

retothejuggler

Dec 12, 2013

#5092
5091

Re: 531, 7531 and so on are not primes, why??
Hi Reto, 737169676563615957555351494745434139373533312927252321191715131197531 is the next prime of this format. Hope this helps, Chris To:

Simba .

Dec 11, 2013

#5091
5090

531, 7531 and so on are not primes, why??
For our juggling club christmas show I`m preparing some numbers and ways to "juggle" them. This way I stumbled on siteswap notation and started to look out for

retothejuggler

Dec 11, 2013

#5090
5089

anyone ever read le calcul rapide (French)
Hello dear calulators and numbers friends :-) Has anyone ever read this book? Henri Wargée Le calcul rapide en vingt-cing leçons If you did, can you

retothejuggler

Dec 4, 2013

#5089
5088

Re: Accidently found factoring record
Dear Reto, The questions I lose are 100% without any expedient. A friend of mine, promoted mathematician and assistant professor, gave me an impression of what

A.W.A.P. Bouman

Nov 20, 2013

#5088
5087

Math Encounters: Secrets of Mental Math
Prepare to be mesmerized as award- winning Harvey Mudd Professor of Mathematics Arthur Benjamin demonstrates (and explains!) how to do rapid mental

mentalmathandcatlover

Nov 19, 2013

#5087
5086

Re: Accidently found factoring record
Dear Willem I agree that this lists are very helpful. But still, puzzling out a 120 digit number is impressive. I`ll present you an easier number here to show

retothejuggler

Nov 19, 2013

#5086Fetching Sponsored Content...

5085

Re: Accidently found factoring record
Dear all, What Mittring has done is fining prime numbers out of a list which contents them. In German it is presented as “einziges Hilfsmittel”. In fact it

A.W.A.P. Bouman

Nov 18, 2013

#5085
5084

Accidently found factoring record
Here http://www.youtube.com/watch?v=vK5uFP28TWY Gert Mittring is factoring very large numbers, at least he finds out how to combine them correctly .:-o.

retothejuggler

Nov 17, 2013

#5084
5083

New Arthur Benjamin videos
Dr. Arthur Benjamin of Harvey Mudd College has 2 new videos out that my fellow mental calculators might enjoy. The first is a 78-minute lecture in Washington,

econalc

Nov 17, 2013

#5083
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