Anonymous
Mar 29, 2026
Rating: 5/5
Essential for Graduate Entrance Prep
I used this daily while preparing for my graduate entrance exams. The equation solver saved me so much time on practice problems. Highly recommended for students.
Description
Reviews
| Brand | - |
| Category | Stationery, Educational Electronics & Office Supplies / Calculators |
| Origin | - |
| Model Number | FC-991CN |
| Display Type | High-resolution LCD with Natural Textbook Display |
| Power Source | Solar panel with backup battery (LR44) |
| Complex Number Support | Yes, including phasor notation and polar/rectangular conversion |
| Matrix Operations | Up to 4x4 matrix calculation and determinant finding |
| Equation Solver | Simultaneous linear equations (up to 4 unknowns) and polynomial roots |
| Base Conversion | Binary, Octal, Decimal, and Hexadecimal modes |
| Language Interface | Chinese (Simplified) menu and prompts |
| Exam Compliance | Approved for most high school and college engineering exams (non-programmable) |
| Dimensions | 16.5 x 8.2 x 1.4 cm |
Anonymous
Mar 29, 2026
Rating: 5/5
Essential for Graduate Entrance Prep
I used this daily while preparing for my graduate entrance exams. The equation solver saved me so much time on practice problems. Highly recommended for students.
Anonymous
Mar 19, 2026
Rating: 5/5
Perfect for Engineering Exams
This calculator handles complex numbers and matrices effortlessly. The Chinese interface is very clear, and it passed my university exam regulations without issue.
Anonymous
Mar 13, 2026
Rating: 5/5
Best choice for Circuit Analysis
As an electrical engineering student, the ability to switch between polar and rectangular forms instantly is a game changer. No text editing features means it's allowed in all my tests.
Anonymous
Mar 08, 2026
Rating: 4/5
Great functionality, steep learning curve
The features are incredible for the price, especially the phasor calculations. However, the manual is dense, so expect to spend some time learning the key combinations.
Anonymous
Mar 06, 2026
Rating: 4/5
Good value but screen could be brighter
Functionally, this matches more expensive brands. My only complaint is that the screen contrast is a bit low in dimly lit lecture halls, but still readable.
Anonymous
Mar 05, 2026
Rating: 5/5
Reliable and Fast
The processing speed is impressive even with large matrices. The solar power works well in classroom lighting, and the build quality feels durable.
Q: Can it solve systems of equations with 4 variables?
A: Absolutely. This model can solve simultaneous linear equations with up to 4 unknowns and also finds roots for polynomial equations up to the 3rd degree.
Q: What type of battery does it use if solar is insufficient?
A: It uses one LR44 button cell battery as a backup power source when ambient light is too low for the solar panel to operate effectively.
Q: How do I perform phasor to rectangular conversion?
A: You can input a complex number in polar form and use the 'CMPLX' mode functions to toggle between polar (r∠θ) and rectangular (a+bi) formats instantly using the shift keys.
Q: Does the menu language switch to English?
A: No, this is the specific Chinese version (CN). The menu, error messages, and prompts are exclusively in Simplified Chinese.
Q: Is this calculator allowed in the National Graduate Entrance Examination?
A: Yes, the FC-991CN is non-programmable and does not have text editing capabilities, making it compliant with most standard university and graduate entrance exam regulations in China.