DUAL POWER: The computer calculator is powered by a dual power supply with solar panels and AA battery (1 AA battery not included) for long life and is not affected by power outages during use. (NOTE: Some users may use the calculator early in the morning or at night. The screen may be difficult to read in low light without battery power. Insert the AA battery for continuous and accurate use.) RESPONSIVE LARGE BUTTON: The large calculator has environmentally friendly plastic keys, more suitable for fingers, comfortable touch, and fast response. COMFORTABLE ANGLE & LARGE SCREEN: The calculator is designed with a raised head, so the screen viewing angle can meet human vision habits. The screen uses a 12-digit LCD display, which can easily and clearly display the screen content. FOUR-POINT NON-SLIP BASE: The bottom of this basic calculator has four points of silicone non-slip pads, which makes the calculator stand stably on the table, stable operation is not easy to slide. MULTI-POPULATION APPLICABILITY: This basic desktop calculator is designed for a wide range of applications: desk office, financial calculations, supermarket calculation, family budgeting, student calculation, etc., to improve efficiency and accuracy.