The Casio FX‑991ES PLUS‑2 (Black) is a premium scientific calculator designed for students, engineers, and professionals. With 417 advanced functions and the intuitive Natural Textbook Display, it lets you input and view expressions exactly as they appear in textbooks—making math and science easier to understand. The sleek black finish adds a professional look, while the solar + battery dual power ensures uninterrupted use during exams or long study sessions. The improved 2nd Edition model offers better navigation keys, a slim profile, and high durability for daily academic or office use. Perfect for high school, university, or competitive exams.