<p>On both tests, I have used (and would recommend) a graphing calculator because of the ability to enter and edit longer problems instead of having to do one operation at a time, the ability to go back and review things you have previously entered, the ability to easily store variables and use them to "plug and chug" into equations, and the ability to graph equations and look at things visually. For the SAT II Math IIC, the TI-89 will put you at an advantage because of its built in features such as the solver, but there's nothing on the test for which a "lower" graphing calculator like a TI-83+ won't suffice. For the SAT I, there are people who swear by the 89, but I don't think there's a need to go out and get a 89 if you already have a 83+ or 84. The features of the 89 might be useful, but the math problems are no where near as complicated as on the IIC and it's quite possible to do well on the SAT I even with out a calculator.</p>
<p>I am sure CB realizes this, but with a graphing calculator, you can pre-input important concepts into your graphing calculator. . .that way, in case you blank out during a math section, you can quickly refresh yourself by reviewing whatever you put in the calculator</p>
<p>This issue comes up a lot!
I would highly recommend a grapher over a scientific because there are some problems you can graph to get the right answers if you dont know it (like ones that ask you what the graph of something looks like).
But as for a Ti-89 vs. 83,84,86... its better to have the latter simply because its cheaper and the 89 wont put you at a much greater advantage. Also, factoring is fairly easy on the SAT and people who rely that much on calculators wont do good either way.</p>
<p>Ti-89 is much a much better calculator in general and I personally think it's more "user-friendly", especially for new users. If money is not that big of an issue (the difference in cost isnt even that great), I'd suggest spending alittle more to get the 89.</p>
<p>Note, however, that the Ti-89 is NOT allowed on the ACT, while the others are.</p>