⭐ Customer Reviews and Testimonials

Authentic User Feedback

🎓 Student User Reviews

⭐⭐⭐⭐⭐ Jessica Lin - Engineering Student
"I’ve been using the CTIFREE fx-991ES PLUS for my calculus and statistics courses since January 2025, and it’s been a game-changer. The 417 functions cover everything I need—from matrix operations to numerical integration. The large LCD display makes it easy to spot errors in complex expressions, and the solar power means I never worry about dead batteries during exams."

Purchase Date: January 2025 | Usage Period: 6 months

🔬 Professional Engineer Reviews

⭐⭐⭐⭐⭐ David Park - Civil Engineer
"This calculator has become my go-to tool on site and in the office. The 'Solve' and 'Table' functions save me hours when analyzing structural loads and creating design models. I especially appreciate the dual power source—it’s still running strong after 8 months of daily use, even under low-light conditions thanks to the backup battery."

Purchase Date: March 2024 | Usage Period: 8 months

🧪 Research Scientist Reviews

⭐⭐⭐⭐☆ Dr. Elena Rodriguez - Research Lab
"While I mostly rely on software for advanced data analysis, the CTIFREE fx-991ES PLUS is perfect for quick statistical calculations and field checks. The statistics mode is intuitive, and the RoHS and CE certifications give me confidence in its reliability. My only minor critique is that the keypad can feel a bit stiff at first, but you get used to it."

Purchase Date: November 2024 | Usage Period: 4 months

🏫 High School Teacher Reviews

⭐⭐⭐⭐⭐ Mr. Thomas Reed - Math Educator
"I recommend this model to all my AP Calculus and Physics students. It strikes the right balance between functionality and usability. The clear multi-line display helps students follow step-by-step solutions, and the customizable modes allow them to switch seamlessly between algebra and statistics. After using it for 5 months, I can confidently say it outperforms other calculators in its class."

Purchase Date: February 2025 | Usage Period: 5 months

📈 University Student Reviews

⭐⭐⭐⭐⭐ Amina Diallo - Economics Major
"As someone who juggles econometrics, finance, and statistics courses, I needed a calculator that could keep up. The matrix and vector functions have been indispensable for regression analysis. I bought mine in September 2024, and it’s held up perfectly through daily campus use. The plastic build is lightweight yet durable, and I love that it’s eco-friendly with solar charging."

Purchase Date: September 2024 | Usage Period: 8 months

📊 Rating Statistics

Average Rating: 4.7/5 ⭐ (94 Reviews)

Detailed Rating Distribution:

• ⭐⭐⭐⭐⭐ (5-star): 72 reviews (76.6%)
• ⭐⭐⭐⭐☆ (4-star): 18 reviews (19.1%)
• ⭐⭐⭐☆☆ (3-star): 3 reviews (3.2%)
• ⭐⭐☆☆☆ (2-star): 1 review (1.1%)
• ⭐☆☆☆☆ (1-star): 0 reviews (0%)

🏆 Industry Expert Recommendations

STEM Education Technology Expert

Dr. Karen Liu - Educational Technology Specialist
"The CTIFREE fx-991ES PLUS stands out in the crowded scientific calculator market due to its optimal blend of functionality and accessibility. With 417 functions and a user-friendly interface, it supports curriculum standards from high school through early university STEM programs. Its dual power system and international certifications make it a sustainable and safe choice for classroom deployment."

Engineering Tools Consultant

Mark Benson - Professional Tools Advisor
"After evaluating over 30 scientific calculators for field engineers, I consistently recommend the fx-991ES PLUS. Its reliable performance in diverse environments, combined with essential features like equation solving and vector math, makes it ideal for real-world engineering tasks. The Advanced Model offers the best value for professionals who need robustness without unnecessary complexity."

💬 Latest User Reviews

Recent 30-Day Review Highlights:

⭐⭐⭐⭐⭐ "Essential for Exam Prep" - Ryan Foster (University Student)

Posted: 2 days ago

"Used this daily while preparing for the FE exam. The 'Table' function helped me visualize equations quickly, and the battery-solar hybrid never failed me during long study sessions. Exceeded my expectations."

⭐⭐⭐⭐⭐ "Perfect for Classroom Use" - Ms. Laura Simmons (High School Teacher)

Posted: 1 week ago

"I bought a class set for my students. The keypad layout is intuitive, and the large display reduces input errors. Very pleased with durability and consistent performance across all units."

⭐⭐⭐⭐☆ "Great Upgrade from Basic Model" - Omar Jenkins (Physics Major)

Posted: 3 weeks ago

"Switched from a basic scientific calculator and noticed the difference immediately. The statistics and matrix modes are powerful, though it took a few days to learn all the shortcuts. Worth the learning curve."

🎯 Reviews by Use Case Category

🎓 Students (High School & University) – (58 Reviews)

• Average Rating: 4.8/5
• Most Praised Features:
  • 417-function capability (88% mentioned)
  • Large, readable display (91% mentioned)
  • Long battery life with solar assist (85% mentioned)

🧑‍💼 Professionals (Engineers, Researchers, Technicians) – (26 Reviews)

• Average Rating: 4.6/5
• Most Praised Features:
  • Solve and Table functions (82% mentioned)
  • Dual power reliability (90% mentioned)
  • Compliance with international standards (77% mentioned)

🏫 Educational Institutions (Classroom & Lab Use) – (10 Reviews)

• Average Rating: 4.7/5
• Most Praised Features:
  • Durability across student users (89% mentioned)
  • Ease of teaching with consistent interface (85% mentioned)
  • Environmentally friendly power system (80% mentioned)