* Professionals and college students have the flexibility no other scientific calculator can offer with the choice of RPN or Algebraic entry system logic. Delivers a large 2-line alphanumeric display with adjustable contrast, raised edges to protect the keys and a robust library of built-in functions and constants. Same time with an impressive array of programmable scientific functions. Have confidence that every time you turn on your calculator you make, results in dependable, worry-free performance and accurate results. Power Source(s): Battery; Display Notation: Engineering;Numeric.