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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
6 years 9 months

Latest Posts and Comments

Title Type Comments Updated
Dividing by full reptend primes Forum topic 5 7 months 4 weeks ago
Fast division by 23 Forum topic 7 7 months 1 week ago
Which is greater? a^b or b^a? Forum topic 3 2 weeks 4 days ago
Best books on Math prodigies and Speed Math Forum topic 5 9 months 3 weeks ago
Paper on calendar calculations – determine the year’s share for the day-of-week Forum topic 1 9 months 3 weeks ago
Calculating logarithms by hand Forum topic 16 3 months 1 week ago
More repetition fun in division Forum topic 2 11 months 4 days ago
Which Is Easier to Calculate? Km to Miles or Vice Versa? Forum topic 2 11 months 2 weeks ago
What is 6÷2(1+2)? Forum topic 7 1 year 6 months ago
Mattias Ribbing Forum topic 2 1 year 7 months ago
Other avenues of attack? Forum topic 30 2 years 1 month ago
How to do divisions to many decimal places mentally? Forum topic 11 3 years 7 months ago
Prime factor mnemonics Forum topic 5 3 years 3 months ago
Calculating 10 ^ 0.1 , 0.2, 0.3, etc Forum topic 5 3 years 8 months ago
Avoiding the carry Forum topic 4 1 year 1 week ago
Memory feat presentation Forum topic 3 1 year 7 months ago
Lattice Multiplication and Drawing Lines Forum topic 5 4 years 1 month ago
Mental Math Resources Forum topic 0 4 years 2 months ago
Famous Mental Calculators Forum topic 3 4 years 2 months ago
Speed calculators: What is really useful to memorize? Forum topic 32 4 years 2 months ago