Graphing calculator recommendations
General advice on graphing calculators:
I am recommending Texas Instruments calculators rather than other brands because (1) TI is the best selling calculator, and therefore will have more standalone documentation and specific keystroke examples in textbooks than any other brand, and (2) I believe that the TI offers the best functionality and ease of use. Every brand has its strengths and weaknesses, but I believe that the TI is the superior brand overall.
I am recommending the TI-83 graphing calculator as the most basic graphing calculator, and it will generally be plenty adequate for any math or science student. I am not recommending the less expensive TI-85 or TI-86, because they are more difficult to use, and the difference in cost is just not worth it. Investing in the right calculator from the beginning will likely save you money in the long run, because buying a cheaper calculator will probably mean that you have to spring for a more expensive one later anyway. Students will get used to using their calculator, and that ease of use will be very important as they learn to use more and more functions on the calculator. They will probably not learn all the functions on the TI-83 unless they end up as math majors in college.
I am also recommending other more advanced calculators. The more advanced calculators certainly add speed and additional capabilities, but it should be noted that more advanced calculators are also more difficult to learn. Therefore, you have to balance your need for "spiffy functionality" with the ease of use. More details follow on each individual calculator.
The TI-83 plus graphing calculator is a must for high school and college math and science students. It is said to be the best selling calculator of all time, and for good reason. This calculator can get you all the way through high school and college math and science. The TI-83 plus is a fairly basic graphing calculator, but has more than enough features even for the serious math/science student. It handles all the basic functions needed for any high school math class and most college math classes as well. It allows you to see a graph, its equation, and coordinates (ordered pairs) all at once. It also has very useful statistical and math functions built in. You may also use this calculator on most Math SAT exams and most Math and science AP exams.
You will also be able to find many many math, science, and finance textbooks with specific keystroke guides for this calculator, and that helps make learning easier.
Also recommended: The "Graphlink" cable for the TI calculators allows you to plug the calculator into your computer and transfer calculator output onto your computer. This extra option is very useful for homework papers that require technology use. Here is a list of compatible calculators: TI-73 Explorer, TI-83, TI-89, TI-92, and Voyage 200.
The TI-84 has essentially all the features of the TI-83 plus, but is 2.5 times as fast, and adds more built in applications. For example, the TI-84 easily graphs conic sections, inequalities, and includes applications that do everything from simulations to science tools. This calculator also has more advanced statistical tools than the TI-83, and better output displays.
The TI-89 has the capabilities of the TI-83 and TI-84 calculators, with added speed and functions. In fact, you probably won't know how to use many of the built-in capabilities. The big difference that all students will notice between the TI-83/84 and TI-89 is that the TI-89 is capable of symbolic manipulations. In other words, it can solve problems algebraically as well as numerically. Because of this, there is a danger of students using it as a crutch instead of a tool, but if used correctly, it is incredibly powerful. It has an advanced display capability, and allows for a huge amount of flexibility. (The only calculator that I know of with a better display is the new Ti-nspire.) The TI-89 also has more advanced programming capabilities than the TI-83/84 calculators.
The TI-89 is allowed on all the SAT exams, as well as the AP exams. However, it is not allowed on the IB Math exams, so make sure to get comfortable with a TI-83+ or TI-84 if you are taking an IB Math exam. Also note that any programs on your calculator will be deleted by the examiner, so back them up at home before the exam. IB will allow the TI-89 for its physics exams.
The TI-nspire is more of a portable computer than a calculator. It has color graphics capability, and the graphics themselves are far better than the older TI calculators. It has a touchpad, and allows multiple views of functions. Mathematical expressions are easily manipulated. This is a fabulous tool for high school and college math students, but they will need the patience to learn to fully use its capabilities.