Can someone help me understanding what is the added value in mental math? Btw to be precise it is not math but algebra.
Let me explain myself: when I interview candidates, I do not ask them to calculate mentally the resistivity of a piece of silicon given the data: it is pointless, any computer can do it faster and better. What I want to know from them is if they can explain me what influences the resistivity and if they can provide a physical explanation for that. I give them complex problem, they can use the smartphone if they like, they will not find the answer there. They have to show me how they think and if they are able to come up with innovative solutions.
In other words, my belief is that doing fast calculations in your head is not synonimus of being a math genius: can you tell me how many winners of the Fields medal were very good in fast mental algebra?
But maybe I'm simply wrong.. thanks!