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DUPOTA

OA-991ES Plus Scientific Calculator with Natural Formula Visualization Display 417 Functions Dual Power & Lightweight Design for High School Students & Teachers

Based on 54 reviews
Condition: New
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$16.98
Save $7.01 was $23.99

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At a glance

Condition
New
Size
991ES PLUS
Model
OA-991ES Plus
Screen size
2.5 in
Weight
125 g
Color
black
Calculator Type
Engineering/Scientific

Features 5

  • Exam ComplianceComplies with STEM-approved standards with exam-mode features that disable advanced functions (local policies may vary). Includes anti-cheating design and clear exam-mode instructionstrusted by educators for standardized test prep.
  • Natural Formula VisualizationDisplays fractions, integrals, and equations in a Classroom-standard format. Step-by-step tracking helps students understand problem-solving logic, while teachers can demonstrate derivative calculations from four perspectives.
  • 417 Calculation FunctionsEngineered for STEM curricula, supporting matrix operations (up to 4x4), vector calculations, 40 metric conversions, and 9 variable memories. Ideal for use in schools, offices, and business, meeting the needs of various fields.
  • Professional-Grade DurabilityShock-resistant design with a 3-layer protective case (scratch-resistant screen, reinforced buttons, and impact-absorbing frame). Dual power (solar/LR44) enhances energy efficiencybuilt to withstand daily classroom use and backpack tosses.

Specs 16

Brand DUPOTA
Color black
Calculator Type Engineering/Scientific
Power Source Solar Powered
Screen Size 2.5 Inches
Number of Batteries 1 LR44 batteries required. (included)
Display Type LCD
Enclosure Material Plastic

Frequently asked questions

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To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews

Nice scientific calculator
Size: 991EX PLUS
I am quite pleased with this calculator. It comes programed with multiple functions, in some cases going beyond a typical scientific calculator. Vector, matrix, probability, integral, or statistical calculations, this calculator can handle surprisingly many of them. As a primary user of TI calculators, I found transitioning to the Dupota calculator a bit challenging due to the learning curve. As long as the protective buyer is okay with that, this solar calculator is extremely powerful and a great choice. ... show more
Reviewed in the United States on December 29, 2024 by RTMPX
My daughter used this in college
Size: 991ES PLUS
It got the job done!
Reviewed in the United States on December 21, 2024 by JG
Convenient
Size: 991EX PLUS
This calculator has been a great tool for school! The 552 functions cover everything I need, and the two-line display makes it easy to track my calculations. It’s reliable, and the solar battery is a huge plus for not having to worry about changing batteries.
Reviewed in the United States on December 22, 2024 by Arman
Going strong
Size: 991ES PLUS
Had to get a non-graphing for a university course. This one fits the bill, sustains small drops, and is pretty comfortable to hold.
Reviewed in the United States on December 10, 2024 by Xoxo
Useful and great price
Size: 991EX PLUS
This calculator is a useful tool for simple math. The solar and battery operation is reliable, and the display is clear and easy to read. It’s lightweight yet durable. It's easy to navigate all the functions, but this calculator gives some answers in fraction form. Sometimes this wasn’t a problem for me, but it was inconvenient on tests. I couldn't figure out which function converts the fraction to a decimal or if it had a function like that at all. ... show more
Reviewed in the United States on December 18, 2024 by Rebekah
Great Calculator for School and Study
Size: 991EX PLUS
The OA-991EX Plus Scientific Calculator is an excellent choice for both students and instructors. It includes 552 functions and can readily handle everything from elementary algebra to more complex computations. The two-line display includes both the issue and the answer, making it simple to follow along. With solar and battery power, you won't have to worry about running out. This calculator is reliable, simple to use, and ideal for students! ... show more
Reviewed in the United States on November 4, 2024 by Shiva
Does what we need it to and appearently a thousand other things.
Size: 991ES PLUS
I got this for my kid to have a calculator that she can take back and forth to school without having to worry so much if it gets damaged or lost. We have another brand name calculator that she leaves at the house, and this one seems to do everything that the more expensive one does. Granted we will probably never need or use 95% of the features. It seems reasonably well made with no issues going back and forth thrown in a backpack. ... show more
Reviewed in the United States on October 27, 2024 by 2L student
great calculator
Size: 991EX PLUS
I have 2 kids that are taking Algebra 2. I debated purchasing the pricey graphing calculator, however, I hesitated. They use an online graphing calculator currently and did not seem motivated to switch. When I was in school, the physical graphing calculator was the way to go, so I asked the guidance counselor for input. They stated that students choose what they prefer, and that it is 50/50 on preference. Mine seem to prefer the online version. With testing in the future, I wanted them to have a scientific calculator, as I feel that this would be what is needed most often (not as much needed with graphing), and it would be quicker than accessing the online one. They agreed and have been using this one to get used to it. There are so many features, so it will take time to learn them and I do not think we will ever need them all, but they are good to have. It is a bit overwhelming, so it is fantastic that they include an instruction book. It is extremely lightweight, which is good. However, it does not feel as sturdy as ones that I have used in the past. So a pro to that is less weight, con is possibly less durable. It does have the sliding protective case, so hopefully that will help. I like that it functions with solar power, so less battery replacements. Overall, we are very pleased with this. It rivals the other brands that we have used and is very reasonable in price. With kids having the option of online graphing calculators in school and for testing, they are not as necessary as they were in the past. The need may change in the future for college courses, but so far so good. ... show more
Reviewed in the United States on September 9, 2024 by Ren10
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