A lasting calculator- Reliable and always correct!

I purchased this calculator when my geometry teacher asked for a scientific calculator three years ago. At first I was a little put off by the number of functions this calculator had, and was confused at first by certain functions. For example, the shift/2nd function and the many new trigonometric features. However, as I began to understand what the buttons were all for, this calculator quickly became a favorite. The numbers are clear, and you can use multiple parenthesis. It responds quickly to your touch, and I do not remember ever getting an incorrect answer.
I used my TI-30Xa all through geometry, trigonometry, pre calculus and AP chemistry! I would still be using it today were I able to find it (Things have a way of disappearing in my house)...
One great thing about this product is that included in the calculator case is a small card that sticks in the lid with instructions for using different functions and formulas.
There are few maintenance costs for this calculator. It runs on these tiny silver batteries, but I have never had to replace it in all my use of it. Also, I have dropped the calculator numerous times and it has never been affected.
The calculator cost me about $14.