I have used TI calculators for a long time. In fact, the first time I was presented with a TI-83 graphing calculator in school, I was overly impressed. The thing about TI calcs that makes them so convenient is that they are relatively straightforward and typically familiar when most graphing calculators provided by schools in-class tend to be of the TI brand.
However. When you’re in the market to purchase a graphing calculator of your own, there tends to be things that you need to consider. Searching online for opinions on comparisons between calculators will typically lend mixed results. The two most well-known giants in the calculator world are pretty much Texas Instruments and Hewlett Packard. Depending on who you talk to, you’ll have someone swear by one and gun down the other. In reality, both companies have made some pretty functional calculators.
The TI-83/84 series is likely the most successful by TI, though I would recommend you look at either the TI-89 Titanium or the TI-nspire CX CAS if it’s TI you’re in the market for. Either way, all four of those calculators will run you at $100+ brand new. Though the TI-83 series has a lot of used calculators laying around for a bargain-price, I personally think it’s best to go with the next best option, especially considering that the TI-83/84 calcs are absent of any CAS functionality.
There is also a rise in Casio’s place in the calculator world. I bought an fx-115ES while I was working through some undergraduate electrical engineering courses and it was an excellent calculator for the then $15 price tag. Surprisingly, the standard fx-115ES is now around $30 on Amazon while it’s Plus version is at the $15 mark. That’s strange. Perhaps the Plus actually lacks functionality? I don’t know. But I do know that it is about the best multi-line non-graphing calculator for the price. There are some Casio calcs with more functionality, however, but they also come with a larger price-tag. For example, the Prism FX-CG10 is a graphing calculator that states provides functionality for Physics and AP Calculus. However, it fails to mention any CAS functionality, and I would be hard-pressed to believe it features any being that it is accepted for use on so many tests, including the SAT. That being said, I would probably expect that the fx-9860 series calculators by Casio would be the best option under the Casio brand. They typically run around $65-70 new on Amazon.
Lastly, there is HP. My first interest in HP calculators came about in, surprisingly, the Orientation for Engineering course I took near the end of my studies for my 2-year Associates degree. The course featured a lot of unit conversions and such, and the teacher constantly held up his HP graphing calculator and hailed it as some sort of holy grail for the task. I never really thought any more about it until a couple of weeks ago. I just happened to get curious about the HP calcs and decided to see how much they ran for. The HP Prime is the most recent product, but the 50g was mentioned to be HP’s competitive offer against the TI-89 Titanium. Being as impressed with the Titanium as I was, I decided to purchase a 50g at the surprising cost of $89.99 – nearly $50 cheaper that the Titanium’s price. Considering that the 50g also has CAS functionality, the $89.99 price tag is unbelievably the best deal for a new calculator in this market – in my opinion.
Whether you’re a TI, HP or Casio enthusiast, if you’re in the market for a new calculator for either engineering studies or for use on an engineering job, I recommend the HP 50g. It’s slightly more expensive that the Casio fx-9860 series calculators while being substantially cheaper than just about any new TI calculator. If you’re unfamiliar with the HP calculators, you may find it to be a relatively steep learning-curve at the start, but the calculator provides nearly any immediate functionality you could need or expect from a hand-held calculator.