TI N-Spire Graphing Calculator for $45.99 (Normally $149.99) May 06, 2012 by Your Name in deal Texas Instruments TI-Nspire Graphing Calculator This graphing calculator features drop-down menus and a glide touchpad for simple operation. The calculator displays multiple representations of a problem and has a built-in interactive geometry feature to help you solve a variety of equations. Great deal! See its over $100 on Amazon: