Dear all, Recently I became a member of this group. I am an instructor of abacus. I am teaching memory techniques as well. Some of my students can do 3 digits...
Susan where in india are you from and who's method do you follow...on the abacus avenue.... Are you under the franchisee of any company? I feel for memory...
Hi all, im a year 10 student from Australia and i got some questions and problems. at school when it comes to maths. i outperform my class collegues in class....
Dear Mahmut, What I feel is that though you are intelligent and hard working you have got some fear for exam - ie tension. First of all you have to be...
... hi susan, you might be right but this only happenes to me in maths quizes and exams no other subject. i got to find out what this problem is so i can fix...
I added u as my friend, I am a teacher in maths, In Bangalore. Please do mail me Jayaram ... The observer is the obsreved-JKdrjayaram@... Send free SMS...
Hello, It is a pleasure for me to announce that I have verified the documentation of a new world record claim. Yusnier Viera Romero from Cuba has broken the...
Hi all the members, I am Manasvi and studying in 8th std from India. I Join this group to know about the world record of mental calculation. And would like to...
On 2007, March 14 in the 18 m Galerie für Zahlenwerte in Akazienstraße 30, 10823 Berlin, http://www.18m-galerie.de/ there will be held the PI-Day 2007 of the...
Hello! At http://de.wikipedia.org/wiki/Kopfrechnen#Rechentricks it is stated that one can derive the Quarter Squares-Rule by transforming the Binomials 1. (a +...
((a + b)/2)^2 = (a^2 + 2ab + b^2)/4 ((a - b)/2)^2 = (a^2 - 2ab + b^2)/4 Subtract the latter from the former, and you get (2ab + 2ab)/4, which is ab. QED. P...
P Scott Horne
patrick.horne@...
Jan 31, 2007 2:43 pm
2161
Thank's for your reply, Scott. I see. It is the proof that the Quarter Squares-Rule produces the result ab. Do you see also how one can derive the identity by...
Fans of the world's greatest ever calendar-calculating double act might enjoy this film. http://www.cbsnews.com/sections/i_video/main500251.shtml?id=2405880n...
It is good to see he is now living with a bit more autonomy than in his youth. Emmanuël rob221b <rob221b@...> a écrit : Fans of the world's greatest...
Hmm. this sounds like a homework question... anyway, a hint to get you started you have ab = ((a + b)^2 - a^2 - b^2)/2 hence ab = ((a + b)^2)/2 - (a^2 + b^2)/2...
Unlike the previous posts, my proof is algebra-free. Just stare at this picture long enough and the rule will appear to you "stereogram-style". Arrange 4...
A I expected, the picture got messed up. I would upload a picture-file to the group, but that feature seems to have been disabled. I place here instead: ...
Hello Rob! Yes, this is it. You could also say 4ab = (a+b)^2 - (a-b)^2 (0) And (a+b)^2 = a^2 + 2ab + b^2 (1) is the 1. Binomische Formel (a-b)^2 = a^2 - 2ab...
Hi everybody! Some time ago I've discovered the world of Mental Calculation. I've bought the book of Bill Handley "Speed Mathematics" but I remained...
f> Now I've bought the book on the Trachtenberg systhem because I've f> read some nice commments on this book. The Idea are very nice. Please, sell it back. ...
Oleg Stepanov
olegstepanov@...
Feb 12, 2007 8:58 am
2172
... Hello Oleg! I also began mental calculation and know some of the books you bought. I have also a book from Ronald W. Doerfler which also denotes general ...
... Also I began writing a book on Mental Calculation myself. I want to cumulate many formulas, simplifications and principles and write it in this book....
Please tell me when you release your book. Can you recommend some books? Best regards Michael ... Datum: Sun, 18 Feb 2007 08:17:31 -0000 Von: "peterschreyfogl"...
George Lane's book "Mind Games - Amazing Mental Arithmetic Tricks Made Easy" comes highly recommended! Andy ... From: Dr. Michael Paridon <dr.m.paridon@...>...
Dear Oleg, thanks for reply. You are telling me that the book of tratchenberg is not good, right? (sorry for my english, I speak italian. Wich book or web do...
... on 18 ... Hello, Congrats to Yusnier. There is no answer to this message but i am curious. What kind of record is it ? Written record ? Best wishes....
Hi Andy, Many thanks indeed for the recommendation; it's very gratifying to know that a fellow expert calculator views my book with such regard. However, I...
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