Performs 535 statistical trigonometric and other functions. WriteView technology displays formulas as written in textbooks. DAL (Direct Algebraic Logic) makes it easy to enter formulas into the calculator. Multi-line playback and editing function. Nine independent memories and four programmable keys. Ability to solve three simultaneous equations two variable statistic functions and fraction calculations. Power Source(s): Battery; Solar; Display Notation: Numeric; Number of Display Digits: 16; Display Characters x Display Lines: 16 x 4.