Price: Under $30 (I bought mine from Amazon) And here is a link from officemax for $22.99:
TI-36X Pro Scientific Calculator 36PRO/1L1/A (Google Affiliate Ad)
Review: The TI-36X PRO is a calculator which seems to be designed specifically for standardized testing. Basically, it takes most of the features of an advanced graphing calculator, such as a TI-89, and puts them in a package that is allowed on your standardized test. I bought this calculator for the FE Exam and I as amazed at how much it could do.
Solver: One of the most powerful features is the numerical solver. You can enter any single variable equation and solve for the variable (a numerical result). This comes is so handy on a test where you are provided a formula and the variable you need to solve for is not isolated. You have to be a little careful, though. The numerical solver only returns one solution, even though if the equation you entered has multiple solutions, and there is no warning. The polynomial solver, on the other hand, does return all possible solutions. Obviously, the equation must be in the form of a polynomial to use this feature but usually that is not a problem. As if that wasn’t enough, there is also a system solver. This can be used when you have a 2x2 or 3x3 linear system of equations. This feature is somewhat duplicative since you can also just transform a representative matrix into reduced row echelon form (rref) on the matrix menu, but oh well.
Calculus: The TI-36X PRO does calculate definite integrals (no indefinite). And the calculator will take the first order derivative of any single variable function, evaluated at a given value. The common theme here is that you will get a numerical result. One thing the calculator does not do is symbolic manipulation, where you will get an answer with variables in it. But still, being able to do integrals and derivatives is very useful. In fact, on the FE Exam I had physics questions which boiled down to simple derivatives (position/velocity/acceleration) and the calculator helped me out tremendously.
Matrices/Vectors: You can create matrices (up to 3x3) and manipulate them using the following functions: Transpose, Inverse, ref, and rref. You can create vectors (up to a dimension of 3) and use the dot product, cross product and magnitude functions.
Electrical: As an electrical engineering student, I was very happy that the calculator made it easy to switch complex numbers from polar to rectangular format. I was also happy with digital/logic type features. You can convert numbers to hexadecimal, binary or octal base and even create logic equations using and, or, xor, not, nand and 2’s complement.
Statistics: I am not a statistics expert, but the calculator give me everything I needed on the FE exam. It has built-in functions which take lists of data points (max 5 per list), and calculates all of the statistics you would ever want (at least on the FE Exam). There is also a linear regression function which I found useful.
Conversion/Constants: The built-in conversion function is very useful. It includes English-Metric, temperature, speed/length, pressure and power/energy conversions. Granted, this feature is somewhat limited to common, basic conversions but often that is exactly what you need. The calculator also contains 20 scientific constants, from the acceleration due to gravity to the charge of an electron. Again, not a comprehensive list but useful nonetheless.
Programming Bugs: I wrote a post (link) all about the programming bug. There is more info on the Wikipedia page for the TI-36 and also here (link). The bug only affects mixed fractions that include \(\pi\), but make sure you try my example to check if your calculator has the bug.
Of course, there are other features of this calculator but I have went over the features I found most interesting and useful. If you are an engineering student or someone else who needs to calculate integrals or derivatives, get a TI-89 or TI-92 and make life easier for yourself. On the other hand, if you are someone who does not do any high level math, get the simplified TI-30X and ditch all the bells and whistles that you don’t need. The TI-36X PRO is in a niche between those extremes. If that is what you need, the TI-36X PRO is for you