I bought my very first ti 86 calculator when I was in middle school, and I had some practical use out of because of the math courses that I took, but then again I was still only using approximately ten percent of its fullest capabilities. hahaha Because I had the same calculator for so many years, I did not have the need to purchase a new one because I already had one, and on top of that, they are kind of pricey to get one. So one was perfectly fine with me. Now moving back onto the calculator. It is very reliable, and it has all the necessary applications and programs and functions needed to perform any kind of calculations or programming. I remember back in the day, I used to install game onto the calculator to play games, and they worked wonderfully! On a side, there are some games from the calculator that are on the iphone app store now which is incredible! The jump from a black and white scientific calculator onto now the world wide known media device application store! I recommend buying this one versus the ti 83, it's just better.