<p>The TI-89 is the dominant leader - probably for good reason. My daughters (math/science/engineering types) really like the TI-89.</p>
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LOL!!</p>
<p>He loves to teach others, and he enjoyed writing these long tutorials, even though it consumed so much time (although not nearly so much time taken up as learning all that stuff in depth in the first place). Hah! He should have listed it as an EC! ...Or, without royalties, would that be "community service?" :)</p>
<p>digmedia:</p>
<p>Really, maybe your son could write a book on it targeted at students which is a group he understands well. It's bound to be better than the book written by TI's tecnical writers. You never know, he could do quite well with this or other opportunities it might open.</p>
<p>Thanks for all the helpful advice. They're thinking that they'll just hang on to their trusty TI 83s for now and see how it goes.</p>
<p>My daughter is going to a math and science residential HS starting in August. They require a Texas Instruments (TI) 89 Titanium. The latest in the TI-89s.</p>
<p>One doesn't need calculators to learn calculus. Once you know it, then you can use some fancy calculator to avoid doing tedious computations (though I'd use software like Maple for symbolic manipulation, and Matlab, or, in my case, R, for computations).</p>