Texas Instruments TI-1795SV Minidesk Calculator, 8-Digit LCDLarge contoured keys and angled SuperView display makes this a good choice for home, office, school or retail. Change sign (+/-) key simplifies entry of negative numbers. Square root key is useful for schoolwork. Dual solar/battery power for use in any lighting condition. Power Source(s): Battery; Solar; Display Notation: Numeric; Number of Display Digits: 8; Memory: 3-Key.