The best calculator you will find.
It is the best calculator on the market. It is this you should have, or TI-83 if you get a used one. It is clearly worth paying double the price of what the TI-82 costs. You will not regret it.
Easy to predict, feels well built and professional.
It takes some time to understand the concept, all functions and logic with the buttons. But once you do, you will not want any other counter.
Buy if you intend to count the math in any way in your life, money well spent.
A little expensive and takes time to learn, but otherwise really good counters.
The tip is to check on eBay if you have time to wait for a week. Got hold of a TI-84 Plus C (olor) Silver Edition of about 800 - from the United States in mint condition. It has rechargeable battery, 2MiB memory and a fresher design, but is not available in Sweden.
This is the standard in high school / college and works well for this purpose. There are lots of programs, tutorials and sites on the net about this. However, it feels old and over praised as compared to all other electronics. The menus on the TI models are messy and functions of such data is scattered in several directions. Cryptic commands feels incredibly antiquated today. The frame store 24 Kb is too small and will end immediately. Zilog 80 processor at 15 MHz is not the fastest, it feels as modern as a home computer from the 80's about. The USB connection is a plus but an old type that require special cable. The good thing is the robust construction and the battery life of the monochrome screen and the "real" batteries.
Where are inclined to buy a Casio to smash the monopoly, but fell to an argument: All the Ti and all instructions and guides are made of Ti. Bought a TI-82 STATS for 549 - but was told that a friend sold his Ti-84 for 400: -. While this may make some more shit, has USB and so on. will do of course also Ti-82an, but build quality is so much better on the Ti-84an. The battery cover, plastan, button feel, even if it does not make me a better student is the fact that you prefer buttons on something good than something not as good.
Very good during my high school years, plugs now Simulation & Game Development 180hp at university and this will do perfectly.
Good with USB for transfer to PC, backup and more.