Large and clear 12 digit display, Dual powered (solar with battery backup) , percentage Calculation, 3-Key Memory, 3 Digit Comma markers, Function command indicator, Key for changing plus/minus sign. This basic desk model has a clear 12 Digit display & is easy to use. It is dual powered and performs the major basic functions: addition (extra big key) , subtraction, multiplication and division & percentage. It also has a square root key and positive and negative number key. It also incorporates a 4-key memory function and a Mark up Key (MU) . Other functions include: 4 Key Memory Mark Up Key Square Root Key % Key Double size + Key Change Sign Key Large plastic keys