The OREVA OR-400-GT is a versatile 12-digit financial calculator designed to meet the needs of both professionals and students. It features a 120-step check and correct function, allowing users to review and amend their calculations for enhanced accuracy. The calculator is powered by both solar energy and a battery, ensuring uninterrupted usage across various lighting conditions. Its large, easy-to-read display and soft keypad contribute to a comfortable user experience. Additionally, the OR-400-GT includes a Grand Total (GT) function, streamlining the summation of multiple calculations. This model is suitable for a range of environments, including offices, classrooms, and personal use.