Used TI-83 Plus – The Texas Instruments TI-83 Plus graphing calculator replaces the TI-83 and can be used for many functions. This calculator is easy to use and is perfect for math and science classes including algebra, geometry, trigonometry, pre-calculus, calculus, physics, chemistry, and biology. This model is enhanced with Flash memory for flexibility in adding calculator programs for additional functionality. Features: 16-character, 8-line display 192KB flash memory, 24KB RAM 7 different graphing styles help to differentiate graphs drawn Advanced statistics functions, including hypothesis testing and calculation of confidence intervals Probability distributions Complex number calculations Financial functions, including time value of money, cash flow and amortization Electronically upgradeable flash memory USB (cable sold separately) and unit-to-unit connectivity (cable sold seperately) Powered by 4 AAA batteries