TI-92 plus
The TI-92 looks more like an ancient predecessor to today's tablet computers than it does like a calculator. It has a full QWERTY keyboard, a CAS (computer algebra system), and can do 3D graphing. This calculator was eventually discontinued in favor of the TI-Voyage, but you can still find them used to this day. The TI-92 continues to have a cult following. If you are thinking about picking one up, keep in mind that because of the QWERTY keyboard, this calculator is banned from virtually every standardized test.
For more information, check out this TI-92 plus review at Tech Powered Math. You can also take a look at the Wikipedia entry on the same topic.
For more information, check out this TI-92 plus review at Tech Powered Math. You can also take a look at the Wikipedia entry on the same topic.