The Casio MS-80B eight-digit desktop calculator meets a variety of business needs. Keep this calculator at your desk for whenever you need answers to math problems. Streamline financial calculations with tax calculation, currency conversion & profit margin functions. Can be operated from solar or battery power, so you can use the calculator both day & night. Three-key memory keeps often used figures accessible for faster calculations, Square root, rounding switch, sign change, grand total, & percent functions help you solve a variety of mathematical problems. Key rollover feature makes sure nothing is lost during high-speed input. Keys are made of plastic. Power Source(s): Battery; Solar; Display Notation: Numeric; Number of Display Digits: 8; Calculators Memory: 3-Key.