Teaching and Learning

An interesting post from Mark Thoma and Frances Woolley about young students not being good in math and being quite dependant on calculators.
I think there is nothing wrong in using calculators as a tool, but surely people should have a sound understanding of things before using them. And this applies to many others things as well.
The point is why do young students seem to be so bad at math and so dependant on calculators even for elementary operations? And of course this leads to the question of how should we teach math and everything else.
My idea is that sometimes the way things are thaught makes student more prone to memorizing or learning how to apply some rules, without deeply understanding them. Sometimes a superficial understanding and a good memory are enough for a good grade, while perhaps the opposite would be more desirable (altough clearly not the first best). Exams should try to test understanding, more than knowledge. Moreover I believe that a deep understanding helps memory as well.

Quoting Eric Mazur:
You can forget facts, but you cannot forget understanding.


Here a debate from the last days about Education in Italy and about the Invalsi test in particular.
Articles: Tito Boeri 1 e 2 su Repubblica.
Analysis: Erich Battistin e Antonio Schizzerotto su lavoce.info.