The Casio FX-991ES Plus 2nd Edition Blue Scientific Calculator combines powerful functionality with a stylish blue design. Featuring 417 built-in functions and a Natural Textbook Display, it allows users to view mathematical expressions exactly as they appear in textbooks. This non-programmable calculator supports advanced calculations including trigonometry, algebra, statistics, matrices, vectors, complex numbers, integration, and differentiation. With its dual power system (solar and battery) and durable slide-on hard case, it is an excellent choice for school, college, university, and engineering students.