Casio Fx 991es Plus 2nd Edition

The Casio FX-991ES PLUS is a popular non-programmable scientific calculator, particularly favored by students in engineering, polytechnic, and science fields. It's known for its "Natural Textbook Display," which presents equations and symbols as they would appear in textbooks, making it easier to read and understand. The calculator boasts 417 functions, including capabilities for statistics, trigonometry, logarithms, calculus (integration and differentiation), and solving various equations.