For a few extra dollars, prefer the Ti 30x Pro if available. It has many more functions - tables, vectors, certain integrals, derivatives, in the same package. The big advantage of it (as well as the Pro and generally the Ti) compared to Casio is that they do not lose the formulas and data you have entered when the calculator is turned off. Casio calculators usually turn off automatically after 10 minutes of inactivity and erase everything that has been entered up to that point, such as formulas, statistical data, values in tables, etc... I am not referring to Casio models that can be programmed or/and have graphics, and I reserve a caveat for the new series that end in -cw.