street smart and comment sense. For instance, to most people it is good enough to know 1+1=2. Or it may be better to most people to know 1+1=2, 4/2=2, 1+_1=0. More these maths is for professionals like scientists or professors.
for most people like Donald Trump Obama bUsh Clinton and NW they really do not need to know too much about math or spend too much time on maths especially on the so called Kumom when they were little kids
our Chinese parents must have this kind of mentality Math is not everything