Actually, I think there's a lot to be said for banning calculators in the class room. When I was a kid calculators were plentiful, and we were allowed to use them even in Junior school. We had to learn our times tables and stuff like that, but all our basic maths work was done using the calculator.
As a result, my mental arithmetic skills are absolutely dreadful. I can do maths, even quite complex maths, but if you ask me to do anything without a calculator... forget it. I think that's a bad thing.
AH.
fully agree - kids today working in my local supermarket or newsagent can't add 1+1 in their heads anymore

(yap.. I'm old... I can still do mental arithmetics)
Tom UK