Does the human calculator stuff really work?

[jim1174]

There are a lot of books and videos that can teach you how to do math in your head. does any of it really work.
Is there a certain book or video that you would recomend

 

[mfb]

It is possible to do math in your head, therefore, yes. Doing it fast and with complicated operations requires a lot of practice and various tricks. I don't know specific books for that.