Scientific Calculator Plus 991
Scientific Calculator Plus 991 is made and published by Tran Duy. AppBrain is an independent app data site and isn't affiliated with Tran Duy. The app name, icon, screenshots and description belong to Tran Duy and are shown as published on the App Store.
AppBrain's verdict
EstablishedLoved by users- Rating on App Store
- 4.67
- 12,544 ratings
- Last updated
- October 22, 2026
- Size
- 169.1 MB
Users love it: 4.7 stars from 12,544 ratings. Its best ranking is #83 in Top Free, Education in Saudi Arabia.
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Store listing
By Tran Duy, from the App StoreDescription by Tran Duy Written by the developer, not by AppBrain. Click to read.
NCalc combines a natural-display scientific calculator, advanced math tools, a full graphing module (as 83/84 calculator), a large formula library, and a comprehensive unit and currency converter—designed for students, engineers, and anyone who loves math.
◉ Main Calculator Features
- Natural display: Enter expressions exactly as in textbooks—fractions, roots, exponents, and more—see results as written on paper.
- Keyboard layout: Matches popular models for familiarity and speed: 115 ES Plus, 991 ES Plus, 300 ES Plus, and 991 EX.
- Symbolic and numeric modes: Perform exact fraction calculation or evaluate numerically when needed.
- Arbitrary precision integers: Work with very large integers without losing accuracy.
- Output types: Choose from fraction, mixed fraction, decimal, repeating decimal, degrees/minutes/seconds, and polar coordinates.
- Angle units: Degree, radian, and gradian (grade).
- Decimal formatter: Display numbers in normal, engineering, engineering SI, scientific, or fixed formats.
- Calculation history: Review and reuse past calculations with ease.
- Copy and paste support for fast data entry and sharing.
◉ Algebra, Calculus, and Core Math
- Algebra calculation: Expansion, factorization, simplification, and more.
- Calculus calculator: Derivatives, integrals, and limits of expressions.
- Complex number calculation: Arithmetic, polar/rectangular conversion, exponential, logarithm, powers, roots, and full trigonometric functions.
◉ Equations and Inequalities
- Equation solver: Solve general equations, plus dedicated solvers for quadratic, cubic, and quartic equations.
- System of equations solver: Solve systems with 2, 3, or 4 variables.
- Inequality solvers: Quadratic, cubic, and quartic inequalities with interval-based solutions.
◉ Matrices and Vectors
- Operations: Addition, subtraction, multiplication for matrices and vectors.
- Advanced tools: Determinant, inverse, transpose, rank, eigenvalues, and eigenvectors.
◉ Statistics and Distributions
- Statistical calculation: Descriptive stats and regression calculation (including a regression plotter).
- Distribution calculation: Normal distribution, binomial distribution, Poisson distribution, t-distribution, chi-square distribution, and F-distribution.
◉ Number Bases and Formats
- Base N calculation: Effortlessly switch between binary, octal, decimal, and hexadecimal, with arithmetic in each base.
◉ Tables, Variables, and Custom Functions
- Table Generator: Generate value tables based on any expression and range.
- Calculator variables: Store values and reuse them across calculations.
- User-defined functions: Create your own functions to streamline repetitive work.
- Built-in constants: A rich set of mathematical and physical constants.
◉ Formulas
- Extensive formula collection: Math and Physics formulas, clearly categorized—ideal for secondary school, high school, and university students.
◉ Unit Converter
- Currency Converter
- 1000+ unit conversions
◉ Graphing as 83, 84 calculator
- Cartesian functions, implicit plots, polar, and parametric.
- Tracing, roots, intersections, extrema, derivative, and integral evaluations on graphs.
◉ Auto-renewing subscription
You may purchase an auto-renewing subscription through an In-App Purchase.
• Auto-renewable subscription
• Your subscription will be charged to your AppStore account at confirmation of purchase and will automatically renew (at the duration selected) unless auto-renew is turned off at least 24 hours before the end of the current period.
• Current subscription may not be cancelled during the active subscription period; however, you can manage your subscription and/or turn off auto-renewal by visiting your AppStore Account Settings after purchase
• Privacy policy and terms of use: https://ncalc-app.web.app/terms-of-services.html
Safety and technology
Found in the app by AppBrain- Price
- Free
- App size
- 169.1 MB
- Content rating
- Medium
Technologies used by Scientific Calculator Plus 991
Releases
Updates seen on the App Store- Version
- 3.6.6
- Launched
- April 2019
No changelog data
Alternatives
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Rankings
App Store top charts- Highest rank
- #83
- Chart
- Top Free
- Education
- Country
- Saudi Arabia
App Store Rankings for Scientific Calculator Plus 991
Top rankings
| Rank | Country | Category | List |
|---|---|---|---|
| 83 | Saudi Arabia | Education | Top Free |
Ranking history in Saudi Arabia
About the app and developer
About Scientific Calculator Plus 991
Scientific Calculator Plus 991 is an education app developed by Tran Duy.
User Ratings
Scientific Calculator Plus 991 is rated 4.67 out of 5 stars. The rating is based on 13 thousand ratings.
App Information
Scientific Calculator Plus 991 is freely available from the App Store. The app size is 169.14 MB. The latest version available is 3.6.6. The last update was on October 22, 2026.
Technical Requirements
The app has a content rating of Medium Maturity. The app has been available on the App Store since April 2019.
Developer information for Tran Duy
Address:
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