Casio fx-991ES Plus Scientific Calculator

, a popular model known for its advanced features and natural textbook display.  Here's some information about this calculator: Natural Textbook Display (Natural-V.P.A.M.): This feature allows mathematical expressions like fractions, roots, logarithms, and integrals to be displayed on the screen exactly as they appear in textbooks, enhancing comprehension and ease of use. Dual Power Source: The calculator operates on both solar power and a battery backup (LR44), ensuring consistent functionality in varying light conditions. Extensive Functionality: It offers 417 built-in functions covering a wide range of mathematical operations, including: Basic arithmetic, fractions, percentages, factorials. Trigonometry, inverse trigonometry, hyperbolic functions, exponentials, and logarithms. Calculus features such as numerical integration and differentiation. Equation solving (linear, quadratic, cubic, simultaneous), matrix and vector calculations, complex numbers, and base-n calculations. Statistical functions, including regression analysis and standard deviation. Advanced Features: Includes multi-replay function, CALC and SOLVE functions, scientific constants, and metric conversions. Recommended Use: Ideal for advanced studies at various levels, including Advanced GCSE, A/AS levels, and Highers.