Geography: “what direction [relative to central london] is this tube stop in?”, English counties (locations), U.S. states (locations, capitals), Canadian territories and provinces (locations and capitals), countries (locations, capitals, and at some point I’ll add flags). (Most of these came from ankiweb originally, but I had to add reverse cards.)
Bayes: conversions between odds, probabilities and decibels (specific numbers and more recently the general formulas)
Miscellaneous: the NATO phonetic alphabet, logs (base 2 of 1.25, 1.5, 1.75, and base 10 of 2 through 9), some words I can never remember how to spell (this turns out not to help), some computer stuff (the order of the arguments in python’s datetime.strptime, and the difference between a left join and a right join), some definitions in machine learning, some historical dates (e.g. wars, first moon landing, introduction of the model T), some historical inflation rates, some astronomical facts.
Also a deck based on the twelve virtues of rationality essay. (This one and most of the bayes one I found through LW.)
I’m not sure most of this is useful, but most of it hasn’t cost me significant effort either.
if you memorize logs, I recommend memorizing natural logs of primes. This is all you need to quickly calculate natural log, log_2, and log_10 of any integer.
You get ln of any number by adding together the natural logs of the prime factors, and you get log_m of n by the formula
log_m(n)=ln(n)/ln(m)
(maybe memorize ln(10) too to make the calculation a little easier)
I can’t do real division in my head, but if I wanted to maximise my logarithm-ability while minimizing my number of cards, I would go for logs base (probably 10) of primes, and 1/log(e) and 1/log(2).
But I’m not too fussed about minimizing cards, or about natural logs. Learning more primes might be helpful, but I can get them approximately. E.g. I don’t have log_10(11) memorized, but I know it’s between log_10(10) and log_10(2*6) which are 1 and 1.08, and it would be closer to the latter (my calculator says 1.041, which is slightly lower than I would have guessed, but if I put it in Anki I’d only go to 1.04 anyway).
Geography: “what direction [relative to central london] is this tube stop in?”, English counties (locations), U.S. states (locations, capitals), Canadian territories and provinces (locations and capitals), countries (locations, capitals, and at some point I’ll add flags). (Most of these came from ankiweb originally, but I had to add reverse cards.)
Bayes: conversions between odds, probabilities and decibels (specific numbers and more recently the general formulas)
Miscellaneous: the NATO phonetic alphabet, logs (base 2 of 1.25, 1.5, 1.75, and base 10 of 2 through 9), some words I can never remember how to spell (this turns out not to help), some computer stuff (the order of the arguments in python’s
datetime.strptime, and the difference between aleft joinand aright join), some definitions in machine learning, some historical dates (e.g. wars, first moon landing, introduction of the model T), some historical inflation rates, some astronomical facts.Also a deck based on the twelve virtues of rationality essay. (This one and most of the bayes one I found through LW.)
I’m not sure most of this is useful, but most of it hasn’t cost me significant effort either.
if you memorize logs, I recommend memorizing natural logs of primes. This is all you need to quickly calculate natural log, log_2, and log_10 of any integer.
You get ln of any number by adding together the natural logs of the prime factors, and you get log_m of n by the formula
log_m(n)=ln(n)/ln(m)
(maybe memorize ln(10) too to make the calculation a little easier)
I can’t do real division in my head, but if I wanted to maximise my logarithm-ability while minimizing my number of cards, I would go for logs base (probably 10) of primes, and 1/log(e) and 1/log(2).
But I’m not too fussed about minimizing cards, or about natural logs. Learning more primes might be helpful, but I can get them approximately. E.g. I don’t have log_10(11) memorized, but I know it’s between log_10(10) and log_10(2*6) which are 1 and 1.08, and it would be closer to the latter (my calculator says 1.041, which is slightly lower than I would have guessed, but if I put it in Anki I’d only go to 1.04 anyway).