While I agree that being able to press forward into abstraction is more valuable than trying different permutations of the same problem, I do think the calculator (or at least a function it serves) has some use.

In particular, it lets you, when first introduced to a topic, play around with it, and get past the hump of "Really? Is that true?" I liked my calculator in high school for letting me experiment. I think that today, though, something like Wolfram Alpha works just as well for that. I do think there's a place for it in education, though.