* Makes it easy to double-check your work. This 12-digit calculator is perfect for desktop use at home or in the office. The two-line display records and shows up to 100 key strokes. Left and right arrow keys allow the user to check entries. Insert and delete keys enable modification and correction of calculations. Parentheses keys enable complex calculations. Other functions include automatic tax keys, selectable decimal and rounding slide switches, percent key, three-key independent memory and automatic power down. Power Source(s): Battery; Solar; Display Notation: Alphanumeric; Number of Display Digits: 12; Display Characters x Display Lines: 12 x 2.