the video does indeed backfire. the 'standard algorithm' is less efficient than most of the other mental calculation tricks. in the trivial case of multiplying

the video does indeed backfire. the 'standard algorithm' is less efficient than most of the other mental calculation tricks. in the trivial case of multiplying two 2-digit numbers it looks easy, but it becomes cumbersome when you're multiplying a column of three 4-digit numbers. it is even worse for division. the reason why old school math teachers like it is because it is easy to teach and grade. regarding other countries: the countries where people are stereotypically good at arithmetic don't teach the 'standard algorithm' as primary. on the other hand, i've seen those books (math teachers in the family) and they aren't very good. text books are a scam. students would do better with a good teacher and cheapo dover paperbacks. there are a couple great ones on speed arithmetic.