What was the first school to teach math?

That is a long time ago Geno.

How many years ago is that?

$$\\2015\; -\; -1650\\ $Two minuses make a plus$\\ =2015+1650\\ =3665\;\;years\\ $That is almost 4 millenium!$\\ $And that is a very long time.$$ $     

So students have been enjoying or getting tortured by mathematics for a VERY LONG TIME!

A papyrus of acient Egypt (approx 1650 BCE), listed (probably) practice problems and instructions. So, instructions in mathematics goes back many centuries.