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greymatters's picture
About me: 

I'm interested in all types of mental improvement, primarily memory techniques and mental math. I have written my own course on basic memory techniques, as well as a book on my own technique for calculating the day for any date. I am also the blogger behind the Grey Matters blog, focusing on techniques for mental improvement.


United States


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Member for
7 years 1 week

Latest Posts and Comments

Title Type Comments Updated
Dividing by full reptend primes Forum topic 5 11 months 53 min ago
Fast division by 23 Forum topic 7 10 months 1 week ago
Which is greater? a^b or b^a? Forum topic 3 3 months 2 weeks ago
Best books on Math prodigies and Speed Math Forum topic 5 1 year 3 weeks ago
Paper on calendar calculations – determine the year’s share for the day-of-week Forum topic 1 1 year 3 weeks ago
Calculating logarithms by hand Forum topic 16 6 months 1 week ago
More repetition fun in division Forum topic 2 1 year 2 months ago
Which Is Easier to Calculate? Km to Miles or Vice Versa? Forum topic 2 1 year 2 months ago
What is 6÷2(1+2)? Forum topic 7 1 year 9 months ago
Mattias Ribbing Forum topic 2 1 year 10 months ago
Other avenues of attack? Forum topic 30 2 years 4 months ago
How to do divisions to many decimal places mentally? Forum topic 11 3 years 10 months ago
Prime factor mnemonics Forum topic 5 3 years 6 months ago
Calculating 10 ^ 0.1 , 0.2, 0.3, etc Forum topic 5 3 years 11 months ago
Avoiding the carry Forum topic 4 1 year 3 months ago
Memory feat presentation Forum topic 3 1 year 10 months ago
Lattice Multiplication and Drawing Lines Forum topic 5 4 years 4 months ago
Mental Math Resources Forum topic 0 4 years 6 months ago
Famous Mental Calculators Forum topic 3 4 years 6 months ago
Speed calculators: What is really useful to memorize? Forum topic 32 4 years 5 months ago