Casio FX‑991ES Plus 2nd Edition — Description & Key Features

Product Overview

The Casio FX-991ES Plus 2nd Edition is a high-function non-programmable scientific calculator suitable for high-school, university, engineering and professional use. It belongs to the ES PLUS series from Casio and is designed to show mathematical expressions the way they appear in textbooks. Standout Features

Here are the key features that make it useful:

• Natural Textbook Display (Natural-V.P.A.M.): Expressions (fractions, roots, integrals, etc.) display just like they do in textbooks.

• Number of Functions: The calculator offers 417 functions in total.

• Two-line/multi-line display: Enables input of expression and output result simultaneously, making it easier to follow steps.

• Dual Power (Solar + Battery): It uses solar power when light is adequate, plus battery backup (e.g., LR44) when light is insufficient.

• Wide range of advanced functions:

  • Fraction calculations, combination & permutation

  • Statistics (list-based STAT data editor, regression, standard deviation)

  • Complex number calculations, vector/matrix operations

  • Numeric: integration, differentiation, equation solving (SOLVE/CALC), table generation, base-n (binary/octal/hex) operations

• Design and usability improvements:

  • Slim, rounded body for comfortable hand-use.

  • Hard slide-on protective case that can be attached in any direction to ease use.

• Dimensions & Weight: Approximately 161.5 × 77 × 11.1 mm, weight about 95 g.

• Display Digits: 10-digit mantissa + 2-digit exponent (10 + 2 display) for scientific notation.

• Authenticity check features: Casio provides a web-based authenticity check (QR code/hologram) to help avoid counterfeits.

Suitable For

• Students of mathematics, physics, engineering, statistics who need powerful functionality but not full graphing capability.

• Exam settings where non-programmable scientific calculators are allowed. Indeed users report it’s accepted in many exams

• Professionals needing a reliable hand-held calculator for complex numeric, vector/matrix, statistical or engineering tasks.