Scientific Calculator for Casio 991ES and 991EX Users
CalcES gives you a free scientific calculator for a 991ES-style practice session. Choose the ES PLUS keypad for an fx-991ES PLUS, the EX keypad for an fx-991EX, or the ClassWiz CW-style keypad for an fx-991CW. The display keeps fractions, roots and calculus expressions in textbook form while you work.
From classroom problems to engineering work
A school problem can start with a fraction and end with a quadratic equation. Enter it once, check the exact answer, and switch to decimal when the question needs an approximation. The CalcES quadratic Guide shows how to enter and check the equation on the calculator. For trigonometry, select degrees or radians before evaluating the expression; compare the result with the identity in your coursework when the working matters as much as the number.
For engineering calculator work, B.Tech and other college STEM courses bring longer calculation chains. Store a value and reuse it in the next calculation, revisit a line in the history, or switch to engineering notation for a physics result. Matrices, determinants, inverses, complex numbers and systems of equations are available when a question moves beyond arithmetic. For calculus, enter a derivative at a point, a definite integral or a limit directly on the calculator.
CalcES also has Indian digit grouping. If a result is easier to read in lakhs or crores, choose that display convention in settings. Grouping changes how a number is shown, not its value. Check the question's required notation before copying an answer into an assignment.
Pick the 991 family you use
For scientific calculator practice in the style of Casio 991 models, choose the family that matches your handheld. CalcES has an ES PLUS-style keypad for the fx-991ES PLUS, an EX-style keypad for the fx-991EX, and a ClassWiz CW-style keypad for the fx-991CW. Select the matching family to use the familiar keys, layout and calculation entry of your handheld while you practise.
CalcES is an independent MathDa product. It is not affiliated with or endorsed by Casio. Casio and the model names mentioned here are trademarks of their respective owners.
Work through the next step
When you need to understand how an answer was reached, open the built-in Tales Math Solver from a calculation. It shows steps for supported problems beside the keypad on a larger screen, or in a sheet on a phone. For a function question, the Graph tab and graphing calculator show the curve, its crossings and where it meets another curve.
If the problem is printed or handwritten, you can take a photo, upload an image or draw the expression. Check the editable input before calculating. A misread minus sign changes the whole solution, especially in a matrix or equation.
Frequently asked questions
Does CalcES work like an fx-991ES PLUS, fx-991EX or fx-991CW?
CalcES supports ES PLUS, EX and CW-style keypads with the familiar keys for equations, matrices, calculus and other common calculations. Choose the family your handheld belongs to and practise in the layout you know. It is an independent tool and is not affiliated with Casio.
Can I use CalcES in a JEE or GATE exam room?
No. CalcES is a website for study and practice. Follow the exam's current equipment rules for the actual test.
Does CalcES support matrices and complex numbers?
Yes. You can work with matrices and complex numbers, along with equations, calculus expressions and engineering notation.
Is it free, and do I need an account?
The calculator is free in your browser without an account. Sign in only if you want your calculation history on another device.
About CalcES
CalcES is a MathDa calculator for studying and checking work. Verify critical results and required rounding with your course materials or handheld.