Is this still a relevant skill-set to be good at these days? I feel like it's a bit like writing cursive or being able to have good handwriting in general. It's just not that useful anymore unless you're in very specialized fields that require you to be good at mental math and even then how many situations are you in where you're put on the spot that you have to mentally solve something? There's probably more useful things to keep in your brain than these types of tricks.
I don't mean to be so negative though. I certainly think it's very fascinating and interesting just from a pure mathematical perspective. However we also have to consider the utilitarian perspective when asking "why" many people aren't good at something like this anymore.
I don't mean to be so negative though. I certainly think it's very fascinating and interesting just from a pure mathematical perspective. However we also have to consider the utilitarian perspective when asking "why" many people aren't good at something like this anymore.