fx-991ES PLUS 2nd edition

Non-programmable scientific calculators

fx-991ES PLUS2nd edition

Redesigned ES PLUS series calculators
featuring easy-to-understand
Natural Textbook Display


Introduces the excellent features of the ES PLUS series 2nd edition


1 Design Simple and easy to use

Optimal education tools realized through a design that emphasizes comfort in the hand, legibility, and usability through the pursuit of simplicity

Instantaneous key recognition and ease of operation, the result of careful attention to design details

  • More comfortable in the hand!

    A rounded design that fits naturally in the hand and a slim body that’s comfortable to hold

  • Attachable and detachable in any direction!

    Hard case that’s attachable and detachable in any direction for greater ease of use

  • More legible!

    The keys have been made rectangular, making them easier to press. They are also easier to read because of larger text.

  • Easier to use!

    Highly visible, easy-to-press cursor keys and function keys

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2 Quality Authentic quality

Excellent quality and authentication ensure confidence and peace of mind for use in educational settings

1Tough & Sustainable

CASIO has established three criteria to ensure excellent quality in the ES PLUS series.

  • 1.Wear-resistant printing

    Since ES PLUS calculators are products used for many years as learning tools, the keys are made of a material that offers high durability and resistance to print peeling.

  • 2.Drop-resistant body

    The high product quality prevents malfunction or breakage when a calculator is dropped.

  • 3.Environmentally friendly

    Compliant with RoHS environmental regulations

    The materials used in ES PLUS series calculators comply with European RoHS environmental regulations, an international standard.

    *Complies with DEHP, BBP, DBP, and DIBP

These three quality features ensure that CASIO ES PLUS series calculators are educational tools that effectively support learning.

2Authenticity Check

Two methods enable authenticity checking before and after purchase.
Furthermore, Premium Content is available to registered users of genuine ES PLUS series calculators.

Web Authenticity Check System

There are two Web Authenticity Check methods. Confirm product authenticity by using a smartphone to scan a QR code attached to the product package or shown on the calculator display.

Before purchase

Check on the calculator packaging

  • STEP1

    A hologram sticker is affixed to the package.
    Please confirm the sticker.

    The photo shows the fx-991ES PLUS 2nd edition.

    Note: The example shown is a simulated QR Code.

  • STEP2

    Read the QR Code section of the hologram sticker affixed to the package with your smartphone.

  • STEP3

    Go to the QR Code link. One of the three pages below will appear.

    • Likely to be a genuine product.

    • May not be a genuine product.

    • Not a genuine product. Please do not purchase.

Note: The Web Authenticity Check estimates the authenticity of the hologram sticker based on QR Code read status trends. This check does not necessarily guarantee the product is genuine.

Hologram sticker

A QR Code and sticker printed with a hologram as shown below are affixed to the product package.

The hologram has an iridescent rainbow color section and a shiny white section, and the CASIO logo is visible.

Note: This differs from the actual colors because color shades vary depending on the direction of the light.
The hologram sticker has the following characteristics that make it difficult to copy.

  • When the sticker is tilted to the left and right, the color changes.
  • When the sticker is rotated, the shading is reversed.

Note: A hologram sticker is affixed in limited countries.

Use the above characteristics to authenticate a product.

After purchase

Check on the product display

  • STEP1

    From the mode selection screen, press the 0 key to display a QR code on the calculator display.

    The photo shows the fx-991ES PLUS 2nd edition.

    Note: The example shown is a simulated QR Code.

  • STEP2

    Scan the QR code with a smartphone to go to the linked webpage.

  • STEP3

    Choose Authenticity Check or User's Guide.

    • Authenticity Check

      Go to the QR Code link. One of the two pages below will appear.

      • Likely to be a genuine product.

      • Not a genuine product.
        Please do not purchase.

    • User's guide

      Go to the User’s Guide Page on website.

“QR code” is a registered trademark of Denso Wave Incorporated in Japan and other countries

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3 Function Natural Textbook Display

Features Natural Textbook Display format for displaying equations and calculation results just as they appear in textbooks

  • Fraction and square root

  • Trigonometry

  • Table

  • Statistical calculations

  • Equation calculations

  • Complex number calculations

  • Matrix calculations

  • Vector calculations

  • SOLVE calculations

  • CALC calculations

  • Integration calculations

  • Differential calculations

  • Scientific constants

  • Metric conversions

Natural Textbook Display models that make it easy to teach and easy to learn!

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4 Premium content A variety of original CASIO content is available to make learning mathematics fun.

Users can access this content by registering after the authentication check.

1Math Game

Become familiar with mathematics while playing a fun game.

Available languages:
English, Thai, Indonesian


Enjoy an original manga linked to the math game.

Available languages:
English, Thai, Indonesian

3Certificate of Authenticity

Download the e-certificate of authenticity with your name and unique identifier code.

Available languages:
English, Thai, Indonesian, Bengali, Traditional Chinese, Spanish, Portuguese, Arabic

4Mock Exam Papers and Exam Preparation Booklet

These books use the fx-991EX when illustrating how to use the calculators.

Mock Exam Papers :
The booklet contains mock exams and tips for use in class.

Available in Pakistan only *

Exam Preparation Booklet :
Commentary and answers

Available in Bangladesh only *

* Availability is current as of Sept. 2019.

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