CASlO fx-991ES PLUS Scientific Calculator with 417 functions in 1 | Ideal Calculator for Students

olve complex mathematics, calculus, and engineering problems with the Casio fx-991ES PLUS Scientific Calculator. Featuring Casio's signature Natural-V.P.A.M. (Natural Textbook Display), this advanced scientific calculator displays mathematical expressions, fractions, roots, integrals, and formulas exactly as they appear in standard textbooks.
Loaded with 417 built-in functions, it easily handles advanced mathematical operations including differential and integral calculus, matrix and vector calculations, complex numbers, equation solving, and list-based statistical analysis. Equipped with Two-Way Power (Solar + Battery backup), it guarantees uninterrupted performance during exams, lab sessions, and classroom lectures. It is the standard, exam-approved calculation tool for secondary, O/A Levels, intermediate, and university engineering and science students.
Key Features

• Natural Textbook Display (Natural-V.P.A.M.): Shows input expressions and results—such as fractions, powers, square roots, and integrals—identically to printed textbook notation for intuitive comprehension.
  
• 417 Advanced Functions: Includes numerical integration & differentiation, matrix operations, vector computations, complex numbers, and equation solvers (CALC & SOLVE).
  
• Two-Way Power (Solar & Battery): Solar-powered in illuminated rooms with an automatic battery backup to ensure it never powers off during crucial exams.
  
• High-Resolution Dot Matrix Screen: 10-digit mantissa + 2-digit exponential display delivers sharp, easy-to-read formulas and table views.
  
• Statistical & Table Functions: List-based STAT data editor for standard deviation, regression analysis, paired-variable statistics, and function table generation.
  
• Scientific Constants & Metric Conversions: Built-in 40 scientific constants and 40 metric unit conversion shortcuts for quick physics and engineering workflows.
  

Specifications

• Brand: Casio
  
• Model: fx-991ES PLUS
  
• Type: Non-Programmable Scientific Calculator
  
• Display: Natural Textbook Display (Dot Matrix, 10 + 2 Digits)
  
• Total Functions: 417 Functions
  
• Power Source: Two-Way Power (Solar Cell + Button Cell Battery)
  
• Memory: 9 Variable Memories
  
• Included Case: Slide-on protective hard cover
  
• Target Audience: Engineering students, A-Level/FSc students, university scholars, and educators
  Note this is a Chinese Variant.