Attributes

Brand	-
Category	Stationery, Educational Electronics & Office Supplies / Calculators
Origin	-
Brand	Casio
Model Number	FX-991CN X / CW
Display Type	High-resolution LCD with Natural Textbook Display
Power Source	Solar + Battery (LR44)
Number of Functions	552+
Memory Slots	9 Variables + Independent Memory
Language Support	Chinese and English Menu
Dimensions	165.5 x 77 x 11.1 mm
Weight	Approx. 105g (with battery)
Warranty	1 Year Manufacturer Warranty

6 reviews

Anonymous

Mar 22, 2026

Rating: 5/5

Best investment for grad school

As a graduate student in economics, I need reliable tools. This Casio model never fails me. The spreadsheet function is surprisingly powerful for quick data analysis without needing a laptop.

Anonymous

Mar 19, 2026

Rating: 5/5

Essential for Chemistry Competitions

Used this during a national chemistry competition. The statistical features and unit conversions saved me so much time. It's robust and fits comfortably in the hand during long exam sessions.

Anonymous

Mar 17, 2026

Rating: 4/5

Good value, steep learning curve

The calculator does everything advertised, but the icon-based menu requires some practice if you are coming from older button-heavy models. Once mastered, it is incredibly efficient. Build quality feels premium.

Anonymous

Mar 11, 2026

Rating: 4/5

Solid upgrade from the old model

The transition from the X series to the CW took a little time because the interface is different, but the functionality is superior. It solves integrals and derivatives quickly. Just wish the manual was more detailed in English.

Anonymous

Mar 09, 2026

Rating: 5/5

Perfect for CPA Exams

This calculator is approved for the CPA exam and handles complex financial calculations effortlessly. The menu system in the CW version is very intuitive once you get used to it. Highly recommended for accounting students.

Anonymous

Mar 04, 2026

Rating: 5/5

Great for University Physics

I bought this for my engineering physics course. The matrix and vector operations are fast, and the display is crisp enough to read complex equations clearly. Battery life is excellent thanks to the solar panel.

5 FAQ

Q: Can it solve systems of linear equations with 4 variables?

A: Yes, the Equation/Func mode supports solving simultaneous linear equations with up to 4 unknowns, as well as polynomial equations up to the 4th degree.

Q: What is the difference between the X and CW versions mentioned in the title?

A: The 'X' refers to the previous generation (FX-991EX) which uses a traditional button menu, while the 'CW' (ClassWiz) is the newer generation with an icon-based navigational interface and higher resolution display. Both share similar calculation capabilities, but the user interface differs significantly.

Q: Is this calculator allowed in the CFA or CPA exams?

A: Yes, the Casio FX-991CN X/CW is generally permitted in CPA exams. However, CFA Institute has a specific list of approved models; please verify the current year's policy as they often require specific non-programmable models. This model is non-programmable and usually compliant for most standard accounting boards.

Q: How long does the battery typically last with regular daily use?

A: With regular daily use in a well-lit environment, the combination of solar power and the backup LR44 battery typically lasts over 2 to 3 years. If used primarily in low-light conditions, the battery may need replacement sooner, approximately every 1-2 years.

Q: Does the package include a protective hard case?

A: The standard package includes a slide-on hard protective case that covers the screen and keypad when not in use. A separate carrying pouch is not included but can be purchased separately.

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