Paul GrahamVerified account

@paulg for multiplying by 11, definitely.

@paulg Yes. Was a child in India. We learnt those things as if our life depended on it.

@paulg I still use speed maths all the time. Habit.

@paulg I learned them, and still occasionally use some multiplying tricks.

@paulg sure, I occasionally use the Michelle Trachtenberg technique, but the Anna Faris method offers more versatility.

@paulg yes, all the time, especially for multiplication.

@paulg I though about it for my nephew. Math Magic is another good one

@paulg once learned it for case interviews a while ago. It's interesting to know under which circumstances the author developed the system.

@paulg I did back in 1969. I found a book in 8th grade. Other than multiplying 11s, which was conceptually easy, all faded in high school.

@paulg I got that book as a kid. I use the multiplication technique all the time.