Dual Power: Solar and Battery (1 AA battery not included), battery for daily use and solar for emergency use. Large Display: 12 digits large LCD display shows numbers clearly and make it easy to read. Sensitive and Big Buttons: Large buttons allow you press comfortably and quickly display the numbers you want on the screen. Used Widely: This calculator can be used in a lot of scenes like business, office, home, school, basic budgeting, restaurant and more. Function: Add, subtract, multiply, divide, backspace, grand total, CE, %, M+/M-/MRC, On/AC Button, and Auto Power-Off.