Eight-digit professional desktop calculator is perfect for business professionals at home or in the office. Functions include: automatic tax keys, percent key, square root key, 3-key independent memory, larger 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: 8; Display Characters x Display Lines: 8 x 1.