The Casio Advanced Scientific Calculator FX 991 CW Plus. Features include high resolution display to display more data for spreadsheets and 4x4 Matrix calculations. Natural textbook display - symbols and numbers appear just as they do in textbook. Simultaneous and polynomial solve. Solar Powered with Battery Backup

Rounded keys for easier input. Numeric integration and differentiation, 552 functuons.   Four tone display makes operations easy. Intuitive navigation with cursor keys. Works with classpad.net