personally I find that calculators can become instrumental later on in a math/physics career.
Personally I adimattly refused to use a calculator in my classes (and was repeatedly admonished by my teachers) until I reached linear algebra. There the professor tated that some sor of calculator capable of matrix algebra would be a requirement. And her method was a good one.
Fr every new section we were not allowed to use the calculator functions for that work (and some of the older sections, although the requirement was relaxed). This allowed us to do numerous computational examples involving 3x3 and 4x4 matrices as a calculator was able to do the row reductions and inverse matrix operations for us, every student in the class had those algorithems memorised and we were required to use them in various proofs.
I wouldn't doubt that some students here could row reduce faster than I could without a calculator, but to me speed isn't as important as the ability to get it done.
similarly if you look at the gram-shmidt orthonormalization process for functions, it is far easier and faster to have a calculator do the integrals and factor the square roots, than to carry out the process by hand.
^keep in mind that for the above eample I am talking about an 89, so all of the square roots and integrals can be handled symbolically.