<h4 data-start="234" data-end="609">Casio FX-991CW Advanced Scientific Calculator Black</h4> <p data-start="234" data-end="609">The Casio FX-991CW Advanced Scientific Calculator Black is a high-performance calculator designed for students, educators, engineers, and professionals who need precise and advanced scientific calculations. Its high-resolution natural textbook display allows mathematical expressions to be shown exactly as written in textbooks, reducing errors and improving comprehension.</p> <p data-start="611" data-end="1063">This advanced calculator offers over 500 functions, including arithmetic, fractions, percentages, square roots, powers, logarithms, trigonometric and hyperbolic functions, factorials, permutations, combinations, statistical calculations, matrix and vector operations, complex numbers, and equation solving. It also features spreadsheet calculations and multi-replay functions, making it highly versatile for academic, technical, and professional use.</p> <p data-start="1065" data-end="1614">The dual power system, combining solar energy with battery backup, ensures consistent performance in all lighting conditions. Durable and responsive keys allow precise input for accurate calculations. Its compact, ergonomic design provides portability for classroom, office, or laboratory use. The sleek black finish adds a professional aesthetic. Ideal for high school and college students, educators, engineers, and technical professionals, the Casio FX-991CW combines accuracy, efficiency, and reliability in one advanced scientific calculator.</p>