[bawolff]

Abaci would actually probably be good for making mental math come naturally.

As a general rule, i am on team - if you need a calculator in math class then you aren't learning math.

[thfuran]

Because if you're studying real math, a calculator wouldn't help?

[cyberax]

Pretty much. You either do every calculation symbolically, or you need a full-blown computer for numeric methods.

[bawolff]

Either that, or you are trying to teach people arithmatic, in which case having them do it by hand is a benefit.