Looking for a TI-89 cheap? You can buy the TI-89 Titanium on Ebay for the absolute lowest price.
One of my favorite graphing calculators with a computer algebra system is made by Texas Instruments, the TI-89 Titanium. The original TI-89, a smaller version of the old TI-92, was released in 1998 after Texas Instruments realized people didn’t want to have to pack a suitcase to bring their calculator to class. The TI-92 was a great calculator, but it was huge and because it had a QWERTY keyboard, it was banned from almost every standardized test. By contrast, the TI-89, which has almost identical menu system and features, is the size of a normal graphing calculator and has is legal on most tests, including the SAT (but not the ACT).
Since 2004, the most recent version of this calculator has been the TI-89 Titanium. The Titanium version has more memory and a sleeker appearance than the original. Texas Instruments still supports this calculator, so you can always go to their website to update the operating system and add free apps as they are released.
Who is the TI-89 Titanium designed for?
This calculator is great for those in late high school and college, particularly those taking calculus or above. It has a computer algebra system, or CAS. This means it can solve equations both for a numerical solution like x=4, but also for an answer where you want x in terms of y (like y=2x+3). This is a really powerful ability to be able to carry around with you.
It’s also a great calculator for most standardized test takers. The TI-89 is legal on most standardized tests. Of the “big 3,” you can use it on the SAT and AP Calculus test but not the ACT. The official stance by the college board is that you won’t gain an advantage on the SAT or AP test by having a CAS-enabled calculator like the TI-89, but in my experience they do. Clever students will find some problems where they can use the advanced features to take an alternate route to the problem or check their solutions in a different way.
Why I recommend the TI-89 Titanium
The first reason to use the TI-89 Titanium is its feature set. This is one of the most advanced graphing calculators ever made. Its CAS will allow you to solve very advanced problems where a TI-84 or Casio 9860GII won’t cut it. Texas Instruments has developed a lot of free apps for this graphing calculator, many of which come on the device, and the rest are easily downloaded from the TI website. And as much as I truly love the TI-Nspire CAS, the TI-89 still has one significant feature that the Nspire CAS does not, 3D graphing, which is important to many students.
I also like the TI-89 Titanium because ease of use on this calculator is really great for such an advanced model. I’ve trained several kids from my math team on the TI-89, and they all picked it up quickly. A lot of this probably has to do with its menu system. The TI-89 Titanium uses a drop down menu system, similar to what most computer programs use today. It was one of the first calculators to have a drop down menu system, and it make the transition to a new calculator easy for most students.
Finally, it’s built like a tank. The TI-89 is one of the most durable calculators I’ve ever used. When you pick it up, you’ll notice immediately how solid it feels in your hands, giving you confidence that it will last for years.
Bottom line
As I said at the beginning of this article, this is one of my favorite graphing calculators with a CAS. It’s a very powerful calculator, and yet, most students learn to use it in a fairly short amount of time. If you’re reading this article, you’re probably trying to convince yourself you’re making the right decision by going with the TI-89 Titanium. It will give you years (maybe decades) of use, and you’ll enjoy learning with it. I can recommend it without reservation. You should buy your TI-89 on Ebay for the absolute best price.
Upgrading from your used calculator to a TI- 89 Titanium? Get cash for your old calculator by selling it on Ebay!