I have daughters 6 and 8 years old. When talking about math with them, it mostly revolves around arithmetic calculus. But then there are plenty of tricks that c

I have daughters 6 and 8 years old. When talking about math with them, it mostly revolves around arithmetic calculus. But then there are plenty of tricks that can be learnt by doing calculations in ones head. Maybe it is not very fashionable these days, but calculating in ones head certainly is a good training and is often a disguised way of doing factoring/expanding.