Trusted, Redesigned Scientific Calculation
The Casio fx-991ES Plus 2nd Edition brings Natural Textbook Display technology to a comfortable, ergonomic design, built for students and professionals handling everyday scientific and mathematical calculations.

417 Functions for Comprehensive Math
Covers basic arithmetic, trigonometric and exponential logarithmic functions, equation solving (linear, quadratic, and cubic), basic statistics (mean, sum, standard deviation, regression), and more — all in one reliable calculator.

Natural Textbook Display
Expressions, fractions, and results display exactly as they appear in textbooks, with a 10-digit mantissa + 2-digit exponential display for precise, easy-to-read results.

Built for Comfort and Speed
A rounded, slim design fits naturally in the hand, with highly visible, easy-to-press cursor and function keys for instantaneous key recognition. Multi-replay lets you quickly recall and edit previously executed formulas.

Table Generation & Data Analysis
Register a function expression to generate a numerical table, view and edit input data with the list-based STAT-data editor, and access scientific constants used across physics and science coursework.

Reliable Power, Everyday Durability
Solar-powered under sufficient light and battery-powered otherwise, with an approximate 3-year main battery life. A versatile hard case attaches and detaches in any direction for added protection.