12 Digit Solar Power and Battery Big Desktop Calculator. Size:147x186x38mm. The 12 Digit Solar Power and Battery Big Desktop Calculator is a highly functional tool designed for both professional and personal use, equipped with dual power sources for reliability and eco-friendliness. It harnesses solar energy for operation in well-lit conditions and switches to battery power in lower light, ensuring uninterrupted usage. The calculator features a large, easy-to-read display capable of handling 12-digit calculations, making it suitable for complex accounting, financial analysis, and everyday arithmetic tasks. Its design prioritises user comfort, incorporating large, soft-touch buttons that provide a tactile and responsive feel for extended periods of data entry without causing finger fatigue. The auto power-off function enhances energy efficiency, automatically shutting down the calculator when not in use to conserve battery life. A standout feature is the Profit Margin function, which simplifies the process of calculating profit margins, making it an invaluable tool for businesses and individuals involved in sales and finance. This big desktop calculator combines practicality with advanced features, offering a comprehensive solution for mathematical calculations, financial planning, and efficient energy use. Its robust construction and intuitive design make it an essential desktop accessory for offices, homes, and educational settings.