TI-1795SV Minidesk CalculatorLarge 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.