Two-line 249-function scientific calculator offers a two line editable natural textbook display that shows how a problem is solved, not just the answer. Editable feature means that a few keystrokes are all that are usually needed to correct an error, rather than re-keying the entire expression. Calculator includes a full slate of functions including stats, fractions, trigonometry, combination and factorial. Provides one independent memory and six constant memories. Solar plus feature protects memory no matter what the lighting conditions. When you are done, a hard case protects the screen.