I'm not so sure about this. In high school, I spent the first two years doing everything using a TI-83+ (Algebra II and Pre-Calc). However, when my TI-83 stoppe

I'm not so sure about this. In high school, I spent the first two years doing everything using a TI-83+ (Algebra II and Pre-Calc). However, when my TI-83 stopped working (and got a TI-89), I stopped using a calculator almost all together. For both years of Calculus, I did all the work by hand, turning to the calculator only at the end when I needed a final result (and usually tried to do that in my head/with pen and paper anyway). I would say the that helped me immensely with understanding not only understanding the material, but being able to work it out faster. I'm now able to roughly estimate (within a decimal point or two) most basic math problems in only slightly longer than it does for most students to do it on a calculator. In fact, I tend to work problems out significantly faster than most students who simply punch everything into a calculator and get the results from there, if only because I understand the problem better from working it out by hand and know better how to approach it. Being able to estimate square roots in my head has been vastly beneficial, and would be a skill well worth knowing.