A business printing calculator without the paper. Twelve-digit desktop calculator that allows you to check up to 150 steps & make corrections. Double zero & triple zero (00, 000) keys let you imput large numbers. Backspace key erases mistakenly entered digits & helps you from having to start over. Other functions include review & auto review, go-to function, correct key, GT memory & three-key memory. Power Source(s): Battery; Solar; Display Notation: Numeric; Number of Display Digits: 12; Display Characters x Display Lines: 12 x 1.