Introduction
This manual provides detailed instructions for the proper use and maintenance of your Casio FX-991CEX CLASSWIZ scientific calculator. Please read this manual thoroughly before using the calculator to ensure optimal performance and longevity.
A front view of the Casio FX-991CEX CLASSWIZ scientific calculator, displaying its screen, solar panel, and full keypad with various function buttons.
1. Setup
1.1 Powering On
The Casio FX-991CEX CLASSWIZ calculator is primarily powered by a solar cell, with a button battery (LR44) providing backup power for memory retention and operation in low light conditions. Ensure sufficient light is available for the solar cell to operate. Press the ON button to turn on the calculator.
1.2 Initial Settings
Upon first use or after a reset, you may need to configure initial settings. Press [SHIFT] then [MENU SETUP] to access the setup menu. Use the arrow keys to navigate and select options such as input/output format, angle unit, and display format.
- Input/Output: Select MathI/MathO for natural display or LineI/LineO for linear display.
- Angle Unit: Choose between Degree, Radian, or Gradian.
- Display Format: Configure number of decimal places or significant figures.
2. Operating Instructions
2.1 Basic Calculations
Enter numbers and operations using the keypad. Press [=] to obtain the result. For example, to calculate 5 + 3, press [5] [+] [3] [=].
2.2 Function Modes
The calculator offers various modes for different types of calculations. Press [MENU] to access the mode selection screen. Common modes include:
- Calculate (COMP): For general arithmetic and function calculations.
- Complex: For complex number calculations.
- Base-N: For binary, octal, decimal, and hexadecimal calculations.
- Matrix: For matrix calculations.
- Vector: For vector calculations.
- Statistics (STAT): For statistical calculations.
- Table: To generate a number table for a function.
- Equation/Func: For solving equations and inequalities.
2.3 Using Secondary Functions
Many keys have secondary functions printed above them. To access these, press the [SHIFT] key (yellow) followed by the desired function key. For alpha characters and variables, press the [ALPHA] key (red) followed by the corresponding key.
2.4 Memory Functions
The calculator includes independent memory (M) and variable memories (A, B, C, D, E, F, X, Y). To store a value, enter the value, press [STO], then press the desired memory key. To recall a value, press [RCL], then the desired memory key.
3. Maintenance
3.1 Cleaning
Wipe the calculator gently with a soft, dry cloth. Do not use abrasive cleaners, solvents, or wet cloths, as these can damage the surface or internal components.
3.2 Storage
Store the calculator in a cool, dry place away from direct sunlight, extreme temperatures, and high humidity. Keep it away from strong magnetic fields.
3.3 Solar Panel Care
Ensure the solar panel is not obstructed during use to maintain optimal power supply. Keep the solar panel clean and free from dust or debris.
4. Troubleshooting
4.1 "Math ERROR" Displayed
This error indicates an invalid mathematical operation (e.g., division by zero, square root of a negative number). Review your input and correct any errors.
4.2 Display is Blank or Dim
- Ensure the calculator is in a well-lit area for the solar panel.
- If the issue persists, the internal button battery may be low. Contact Casio support for battery replacement information.
4.3 Calculator Not Responding
If the calculator becomes unresponsive, try performing a reset. Locate the RESET button (usually a small hole on the back or side) and gently press it with a thin, pointed object (like a straightened paper clip). Note that this will clear all memory and settings.
5. Specifications
| Model Name | FX-991CEX |
| Brand | Casio |
| Dimensions (L x W x H) | 25.4 x 5.1 x 6.9 cm (approx.) |
| Weight | 240 g (approx.) |
| Power Source | Solar power with button battery backup |
| Display | High-resolution LCD, 12-digit display |
| Key Features | Natural Textbook Display, 552 functions, QR Code generation, Spreadsheet, Equation Solver, Matrix/Vector calculations. |
6. Warranty and Support
Your Casio FX-991CEX CLASSWIZ calculator comes with a standard manufacturer's warranty. For specific warranty terms, service, or technical support, please refer to the official Casio website or contact your local Casio distributor.
Official Casio Support: www.casio.com/support
