Ten-digit professional desktop calculator is perfect for business professionals at home or in the office. The EL-M335BBL is finished in a dark blue design and features a large angled LCD display and durable plastic keys. Functions include: currency conversion functions, automatic tax keys, percent key, backspace key, 3 key independent memory, extra-large plus key, sign change, and automatic power down. Operates on twin power (solar/battery backup). Power Source(s): Battery; Solar; Display Notation: Numeric; Number of Display Digits: 10; Display Characters x Display Lines: 10 x 1.