Casio FX-991MS 2nd Gen Non-Programmable Scientific Calculator. Features: This calculator offers 401 functions, including differentiation, integration, statistics, regression, matrices, and vectors, making it suitable for various academic and competitive exams. Display: It features a 2-line Dot-Matrix display for clear viewing of expressions and results, utilizing S-V.P.A.M. (Super Visually Perfect Algebraic Method) for enhanced usability. Durability & Design: The 2nd edition boasts a sleek, ergonomic design with curved edges for comfort and portability. It's built with wear-resistant key legends and a drop-resistant body, making it durable for student use. Power Source: It operates on dual power, utilizing solar power when sufficient light is available and switching to battery power (LR44) when light is insufficient.