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Scientific Calculator fx-991

Scientific Calculator fx-991

Step-by-step Math Solver

451 ratings
77 reviews
With Ads
📚 Education
Free
In-App PurchasesWith Ads

Price history

Details

Released
February 28, 2023
Updated
October 23, 2026

Features

Developer

Dinh Phuc
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About

This app provides a powerful scientific calculator with step-by-step solutions for equations, advanced functions, and graphing capabilities. It includes a formula library and unit converter, inspired by a popular Casio model, to aid in learning and problem-solving for math and science subjects.

✓Step-by-step equation solver
✓Advanced scientific functions
✓Graphing mode
✓Formula library
✓Unit converter
✓Casio fx-991 inspired interface
Show original description

What users say about Scientific Calculator fx

Reviews of Scientific Calculator fx are mostly positive: the Education app is rated 4.6/5 from 451 App Store ratings. What users like most: very helpful for classes, free to use. Top complaints: latest update inconvenient, update overrides calculations. Summarized from real user reviews.

Positive things

  • 👍Very helpful for classes
  • 💰Free to use
  • 👍Useful without physical calculator
  • 👍Good for engineering students
  • 👍Handles imaginary numbers
  • 👍Super easy to use
  • 🚀Fast and easy to use
  • 👍Very helpful
  • 👍Exactly like physical calculator
  • 👍Faster than normal calculator
  • 👍Accurate and easy to use
  • 👍Replaced physical calculator
  • 👍Useful for school
  • 👍Good for revision
  • 👍Similar to Casio
  • 👍Convenient interface
  • 👍Aesthetic and good for math
  • 👍User interface is great
  • 👍Genuine with many functions
  • 👍Helpful for exams
  • 👍Precise calculations
  • 👍Complete and easy

Negative things

  • 🐛Latest update inconvenient
  • 🐛Update overrides calculations
  • 🐛Mistake in challenge section
  • 🐛Removed important buttons
  • 🐛Cannot find pi button
  • 🐛Simplified interface
  • 🐛Duplicate log key
  • 🐛Cannot change keyboard layout
  • 🐛No 3-dot menu
  • 🐛Can't upgrade to paid version
  • 🐛App crashes on loading screen
  • 🐛App closes on opening
  • 🐛New layout missing CW
  • 🐛'i' key not working after update
See all reviews

What's New in Scientific Calculator fx

1.9.3

October 23, 2026

- Added Daily Challenge with 10 new math questions every day. - Track your personal progress and compete on the 7-day leaderboard.

2

Subscriptions & In-App Purchases

Monthly Premium Access

Full access to premium features for one month

$1.991 Month
How to cancel Scientific Calculator fx subscription ⁉️

User reviews

Most RecentHighest RatedLowest Rated

Must download

When I saw this I thought it was one of those scam ones that make you watch ads every 1sec, so I checked the reviews others have given and I have sto say they weren’t lying I love it, it give you options not like Normal phone calc message to the developer : thank you for taking your time to make this app☺️☺️☺️🫡👏❤️❤️
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TTj22-44

It’s free and it works

It does what it says and the adds aren’t distracting and they don’t interrupt access to the calculator. There’s an option to pay but the paywall isn’t restricting me from anything I need to use.
LBL Brower

Response from developer

We truly appreciate your feedback! ❤️ If there's any feature you’d like to see or improvements you need, let us know. We are always listening and working to make the app even better! 📈

🐒

Built just like my actual fx 991 plus thanks
🌞🌞Vicky

Response from developer

Yes, We'll

.

Its good but the ads is very annoying.
CCR7xTITAN

Response from developer

Thank you for your feedback. We are sorry that you did not have a good experience with our app. Please let us know the issue you encountered so we can improve in future updates! You can contact us at calculator570team@gmail.com.

good app for when you don’t have a physical calculator

really solid calculator app, i’ve used for years whenever i don’t have my t-84 and it does the job. has saved my butt many times!
🎤🎤🐢
See 72 more reviews

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User experience

🐞

Reported Bugs

6 issues

App crashes on loading screen

Bug

App closes immediately on opening

Bug

App crashes on iOS 18

Bug

App closes after update

Bug

Cannot upgrade to paid version

Bug

'i' key not working after update

Bug
✨

Requested Features

4 requests

Fix update issue with calculation display

Feature

Fix duplicate log key in Fx-350 layout

Feature

Add CW layout for Casio fx991 cw

Feature

Change ☐² to X² and ☐⁻¹ to X⁻¹

Feature

FAQ

What does the Scientific Calculator fx-991 app do?

This app functions as a powerful scientific calculator designed to help users solve math and science problems. It offers step-by-step solutions for equations, advanced mathematical functions, interactive graphing, an extensive formula library, and a unit converter.

What are the key features of this calculator app?

Key features include a step-by-step equation solver, advanced scientific functions for algebra and calculus, a graphing mode to visualize functions, a comprehensive formula library for math, physics, and chemistry, and a unit converter. It also boasts an interface inspired by the Casio fx-991.

Is this app free to use?

The app is available for free download and use, but it does contain in-app purchases and advertisements. Users may choose to purchase additional features or remove ads through these in-app options.

Who would benefit from using this app?

This app is ideal for high school and college students studying math, physics, and chemistry, as well as engineers and professionals in STEM fields. Its comprehensive features and step-by-step solutions make complex calculations and learning more accessible.

What kind of math problems can this calculator solve?

The calculator can handle a wide range of math problems, including algebra, fractions, trigonometry, derivatives, and integrals. It provides detailed step-by-step solutions to help users understand the problem-solving process.