A graphing calculator is an essential tool in the study of mathematics. The TI84 is the tried and true standard: it will meet the needs through Algebra, Pre-Calculus and Statistics, it is allowed on the SAT and ACT as well as those AP and IB exams that allow calculators, and its usefulness will carry through to university studies after high school. The limited number of school calculators are used in some classrooms and are aging. A student’s personal calculator is an investment in their education.