energy source solar, batterycolor silverNumber of batteries 1 AA battery required (battery not included).About this projectLarge LCD Display12 digits make the calculator most useful for large calculations. When you put this large display calculator on the desktop, the 30 display is directly opposite your line of sight, which is clearer than the straight display.Large Sensitive ButtonsWith the responsive buttons of this basic calculator, your calculation process will be faster and smoother. The larger, concave buttons match the curvature of your fingertips and are very tactile. When pressed, the button quickly registers and displays the corresponding number on the screen.Dual Power SupplyThe calculator uses a high conversion rate solar panel, the solar energy can be used in a well-lit place, or it can be powered by batteries. The solar calculator will shut down automatically after 10 minutes of inactivity.Wide UseStandard functions of the calculator are ideal for office, business, school, store, mall and office home use. The calculator performs efficiently for everyone and is easy to use by all ages, including children and seniors. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.