Introduction
This manual provides detailed instructions for the proper use and maintenance of your Casio fx-991AR X Scientific Calculator. Please read this manual thoroughly before using the calculator to ensure correct operation and to maximize its capabilities. Keep this manual for future reference.
Product Overview
Key Features
- Display expressions as they appear in textbooks.
- Supports both Arabic and English languages.
- 542 built-in functions for various scientific and engineering calculations.
- High-resolution screen for clear display of graphs and data.
- Two-way power system: Solar cell and LR44 button-type battery.
- List-based STAT data editor for statistical analysis.
- Integration, Differential Equation, Matrix, Vector, and Complex Number calculations.
- CALC and SOLVE functions.
- Base-n calculations and Logical operations.
- 40 scientific constants and 40 metric conversions.
- 9 variable memories.
- QR code generator for data visualization.
Calculator Components
Figure 1: Casio fx-991AR X Scientific Calculator alongside a page from its instruction manual, illustrating its compact design and display capabilities.
The calculator features a full dot display, plastic keys, and a hard case for protection. Key areas include the display, function keys, numeric keypad, and navigation buttons.
Setup
Power Source
The Casio fx-991AR X operates on a two-way power system: a solar cell and one LR44 button-type battery. Ensure the battery is correctly installed. The solar cell provides power in well-lit environments, extending battery life.
Initial Settings
- Press the ON button to turn on the calculator.
- If prompted, select your preferred display language (Arabic or English) using the navigation keys and pressing =.
- Adjust display contrast if necessary via the SHIFT + MENU SETUP options.
Operating Instructions
Basic Operations
- Arithmetic Calculations: Enter numbers and operators (+, -, x, ÷) then press =.
- Parentheses: Use ( and ) for grouping expressions.
- Power On/Off: Press ON to turn on. Press SHIFT then AC (OFF) to turn off.
- Clear Entry/All Clear: Press DEL to delete the last character. Press AC to clear the current calculation.
- Answer Memory: The result of the last calculation is stored in Ans memory. Press Ans to recall it.
Advanced Functions
Figure 2: Detailed view of the Casio fx-991AR X keypad, highlighting the various function keys and the multi-line display.
The fx-991AR X offers a wide range of advanced functions. Refer to the on-screen menu (MENU SETUP) for specific modes and operations.
- Trigonometric Functions: Use sin, cos, tan keys. For inverse functions, press SHIFT first.
- Logarithmic and Exponential Functions: Use log, ln, 10x, ex keys.
- Statistical Calculations: Enter STAT mode via MENU SETUP to perform standard deviation, regression analysis, etc.
- Matrix/Vector Calculations: Access these modes through MENU SETUP to define and manipulate matrices and vectors.
- Equation Solver: Use the SOLVE function (often SHIFT + CALC) to solve equations.
- Unit Conversions & Constants: Press SHIFT + CONST or SHIFT + CONV to access scientific constants and metric conversions.
Maintenance
- Cleaning: Wipe the calculator with a soft, dry cloth. Do not use abrasive cleaners or solvents.
- Storage: Store the calculator in its hard case when not in use to protect it from dust and impact. Avoid exposing it to extreme temperatures or humidity.
- Battery Replacement: If the display becomes dim or calculations are erratic, replace the LR44 battery. Ensure the calculator is off before replacing the battery.
Troubleshooting
- Calculator does not turn on: Check battery installation. Ensure sufficient light for the solar cell.
- Incorrect results: Verify input values and calculation mode. Reset the calculator if necessary (refer to the manual for reset procedure, usually SHIFT + CLR).
- Display is dim: Replace the LR44 battery. Ensure adequate lighting for the solar panel.
- Error messages: Consult the full Casio fx-991AR X manual for specific error code explanations and solutions. Common errors include "Math ERROR" (invalid mathematical operation) and "Syntax ERROR" (incorrect expression input).
Specifications
| Feature | Detail |
|---|---|
| Model Name | fx-991AR X |
| Number of Functions | 542 |
| Display | Full Dot Display, 10-digit mantissa + 2-digit exponential |
| Power Source | Two-way (Solar & 1 x LR44 battery) |
| Battery Life | Approx. 2 years (if used 1 hour daily) |
| Dimensions (H x W x D) | 11.1 × 77.0 × 165.5 mm |
| Weight | Approx. 90 g (including battery) |
| Material | Plastic |
| Languages | Arabic, English |
| Main Accessory | Hard case |
Warranty and Support
For warranty information and customer support, please refer to the warranty card included with your product or visit the official Casio website. Keep your purchase receipt as proof of purchase.
