The Texas Instruments TI-89 Graphing Calculator is a reliable tool for any math or science student. With its regular display size, it is easy to read and navigate through calculations. This calculator runs on batteries and has various functions for graphing and solving equations. The TI-89 model from Texas Instruments is a great investment for those looking for a reliable and efficient calculator. Its brand reputation ensures quality and durability. Whether for business or industrial use, this calculator is a great addition to any workspace.