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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 5 months

Latest Posts and Comments

Title Type Comments Updated
Dividing by full reptend primes Forum topic 5 3 months 3 weeks ago
Fast division by 23 Forum topic 7 3 months 1 week ago
Which is greater? a^b or b^a? Forum topic 1 5 months 3 weeks ago
Best books on Math prodigies and Speed Math Forum topic 5 5 months 3 weeks ago
Paper on calendar calculations – determine the year’s share for the day-of-week Forum topic 1 5 months 3 weeks ago
Calculating logarithms by hand Forum topic 15 2 weeks 3 days ago
More repetition fun in division Forum topic 2 7 months 2 days ago
Which Is Easier to Calculate? Km to Miles or Vice Versa? Forum topic 2 7 months 2 weeks ago
What is 6÷2(1+2)? Forum topic 7 1 year 2 months ago
Mattias Ribbing Forum topic 2 1 year 3 months ago
Other avenues of attack? Forum topic 30 1 year 9 months ago
How to do divisions to many decimal places mentally? Forum topic 11 3 years 3 months ago
Prime factor mnemonics Forum topic 5 2 years 11 months ago
Calculating 10 ^ 0.1 , 0.2, 0.3, etc Forum topic 5 3 years 4 months ago
Avoiding the carry Forum topic 4 8 months 1 week ago
Memory feat presentation Forum topic 3 1 year 3 months ago
Lattice Multiplication and Drawing Lines Forum topic 5 3 years 9 months ago
Mental Math Resources Forum topic 0 3 years 11 months ago
Famous Mental Calculators Forum topic 3 3 years 11 months ago
Speed calculators: What is really useful to memorize? Forum topic 32 3 years 10 months ago