Увод
The Casio FX-991EX is an advanced scientific calculator designed for a wide range of mathematical and scientific applications. It features a Natural-V.P.A.M. display, which presents mathematical expressions and results in a textbook-like format, enhancing clarity and understanding. This calculator is equipped with 552 functions, making it suitable for advanced GCSE, A/AS level, and higher education.

Image: The Casio FX-991EX calculator, showcasing its display and key layout.
Сетуп
Извор напајања
The FX-991EX calculator operates using both solar power and a single LR54 button cell battery. The solar panel provides power in well-lit environments, while the battery serves as a backup, ensuring continuous operation even in low-light conditions. The battery is included with the calculator.
Укључивање и искључивање
- Да бисте укључили калкулатор, притисните тастер [НА] дугме.
- Да бисте искључили калкулатор, притисните [СМЕНА] затим [AC] (ВАН).
Упутство за употребу
Основне операције
The calculator's Natural-V.P.A.M. display allows for input and display of fractions, roots, and other mathematical expressions as they are written in textbooks. This feature simplifies complex calculations and improves readability.

Слика: Крупни план view of the Casio FX-991EX keypad, highlighting the layout of numerical and function keys.
Напредне функције
The FX-991EX offers 552 mathematical functions, including:
- Решавач једначина: Solves linear, quadratic, cubic, and other equations.
- Inequalities: Solves various types of inequalities.
- Table Function: Generates a table of values for a given function.
- Matrix / Vector Calculations: Performs operations with matrices and vectors.
- Израчунавање комплексних бројева: Handles calculations involving complex numbers.
- Prime Factorisation: Determines the prime factors of a number.
- вероватноћа: Includes functions for permutations and combinations.
- Статистика: Supports statistical calculations and distribution analysis.
- Trigonometric and Inverse Trigonometric Functions: Standard trigonometric operations.
- Exponential and Logarithmic Functions: Calculations involving exponents and logarithms.
- Израчунавање разломака: Direct input and calculation with fractions.
- Base-n Calculations: Performs calculations in binary, octal, decimal, and hexadecimal bases.
- Метричке конверзије: Features 40 built-in metric conversion pairs.
- Scientific Constants: Access to 47 common scientific constants.
- Променљиве меморије: Stores values in multiple memory variables.
QR Code Function
The calculator includes a QR code function that allows for online visualization of graphs and other data. By pressing the [QR] button, a QR code is generated on the display, which can be scanned with a smartphone or tablet to access online resources and visual representations of your calculations.

Image: The back of the Casio FX-991EX packaging, detailing key features including the QR code function and various mathematical capabilities.
Одржавање
Чишћење
To clean the calculator, wipe it with a soft, dry cloth. Avoid using abrasive cleaners, solvents, or harsh chemicals, as these can damage the casinг и приказ.
Замена батерије
The calculator uses one LR54 button cell battery. When the display becomes dim or calculations are inconsistent, it may be time to replace the battery. Refer to the detailed instructions in the printed manual for safe battery replacement procedures.
Складиштење
Store the calculator in a cool, dry place away from direct sunlight and extreme temperatures. When not in use, keep the calculator in its protective case to prevent damage to the keys and display.

Image: The Casio FX-991EX calculator shown alongside its protective hard case, designed for safe storage and transport.
Решавање проблема
Уобичајени проблеми и решења
- Екран је празан: Ensure the calculator is turned on. Check battery level and replace if necessary. Ensure sufficient light for solar power.
- Incorrect results: Verify input values and calculation mode (e.g., DEG/RAD/GRA). Clear all memory and reset settings if needed.
- Калкулатор се замрзава: Притисните тастер [РЕСЕТОВАЊЕ] button located on the back of the calculator using a thin, pointed object (e.g., a straightened paper clip). This will clear all memory and return settings to default.
Ресетовање калкулатора
If the calculator behaves unexpectedly or you wish to restore it to its factory default settings, perform a reset. Press [СМЕНА] затим [9] (CLR) and select the desired reset option (e.g., Setup, Memory, All). Confirm your selection to proceed with the reset.
Спецификације
| Феатуре | Спецификација |
|---|---|
| Бранд | Цасио |
| Назив модела | FX-991EX |
| Тип | Научни калкулатор |
| Боја | Црно |
| Извор напајања | Solar and Battery (1 x LR54 included) |
| Број функција | 552 |
| Дисплаи Типе | Natural Textbook Display (Natural-V.P.A.M.) |
| Материјал | Пластика |
| Димензије производа (Д x Ш) | 16.8 цм к 8.2 цм |
| Тежина артикла | 3.18 унци |
| Међународни код артикла (EAN) | 04549526603327 |

Image: The Casio FX-991EX calculator with an overlay indicating its dimensions (6.4 inches / 16 cm in length).
Гаранција и подршка
For detailed information regarding the product warranty, please refer to the warranty card included with your calculator or visit the official Casio website. Technical support and further assistance can also be found through Casio's customer service channels. Please have your model number (FX-991EX) and International Article Code (04549526603327) available when contacting support.





