The Texas Instruments TI-80 includes a lot of math equations and functions that make it a useful graphing calculator for Algebra and Pre-Calculus students. This Texas Instruments calculator has a 64 X 48 pixels screen that displays 8-lines, each containing 16-characters. The handheld Texas Instruments TI-80 is powered by two CR2032 lithium batteries and comes with a protective case. The keys on this graphing calculator are large and color-coded, making it easy for you to locate specific functions. Packed with a 980 KHz CPU and 7K RAM memory this Texas Instruments calculator performs your tasks fast and even retains them for future recall.