Scientific Calculator fx-991EX
Not in any tracked top chart right now.
Updated 25 Oct 2026 · rankings refresh through the day
DeveloperOmer Duman
CategoryEducation
PriceFree
Released
Rating★ 3.1 (7)
Version2.0.9
Age rating4+
First seen by us
24 Oct 2026
24 Oct 2026Installs (est.)1k+ worldwide
Rating
3.1 ★
7 ratings
Measured
Scientific Calculator fx-991EX on the App Store
App details
App ID
6760968561
Publisher
Omer Duman
On the store since
Apr 2026
Under a year
Minimum OS
iOS 17.0+
iPhone XS and later
Devices
iPhone · iPad
Universal purchase
Content rating
4+
Languages
1
EN
Size
18 MB
Also listed in
Developer Tools
Scientific Calculator fx-991EX downloads
Worldwide, per day, and installs to date. The band is open; the exact number is free with an account.
How this is calculated
Apple publishes no download counts. iPhone downloads come from chart positions and daily rating growth per country, calibrated on Google Play install counts; lifetime installs from ratings worldwide × installs per rating. Confidence is the chance the real number is within half to double ours.
Active users
All platforms, worldwide. Free with an account.
Stickiness (DAU / MAU)
how many monthly users open it on a given day
How this is calculated
Monthly users come from lifetime installs across every store, fitted on monthly active user figures companies publish; daily users = monthly × the typical daily/monthly ratio for the category. Confidence is the chance the real number is within half to double ours.
Where it ranks now
Every top chart it appears in across 30 countries.
| Country | Charts | Rank |
|---|---|---|
| Not charting right now. | ||
Ratings
App Store, worldwide.
Rating
3.1 ★
7 ratings
Measured
Ratings
7
Measured
About Scientific Calculator fx-991EX
Scientific Calculator fx-991EX is an academic-level scientific calculator that solves mathematical expressions in natural textbook format — fractions with horizontal bars, square roots with radical signs, and powers with superscripts, rendered exactly as they appear in your textbook.
Built for university students, engineers, researchers, and professionals who need precision and clarity in every calculation.
NATURAL TEXTBOOK DISPLAY
Enter and view expressions in two-dimensional textbook notation. Fractions, radicals, and exponents are displayed in their true mathematical form — not as flat text. Switch between Natural Display (MathIO) and Linear Display (LineIO) anytime.
EXACT FORM RESULTS
Get results as simplified fractions, square roots, and π expressions — not just decimals. Toggle between exact and decimal forms instantly with S⟷D. The calculator automatically detects when a result can be expressed exactly.
COMPLETE TRIGONOMETRY
All standard and inverse trigonometric functions: sin, cos, tan, sin⁻¹, cos⁻¹, tan⁻¹. Three angle modes: Degrees, Radians, and Gradians. Near-zero results are snapped to exact zero to eliminate floating-point artifacts.
FULL COMPLEX NUMBER SUPPORT
Enter and compute with complex numbers in rectangular (a+bi) or polar (r∠θ) form. Access conjugate, magnitude, argument, real part, and imaginary part functions. Convert between rectangular and polar coordinates with Pol and Rec.
FRACTIONS & MIXED NUMBERS
Work with improper fractions and mixed numbers. Results are automatically reduced. Switch between mixed fraction (a b/c) and improper fraction (d/c) display with one tap.
POWER & ROOT FUNCTIONS
Square, cube root, nth root, arbitrary powers, reciprocal, 10^x, and e^x — all rendered in proper mathematical notation with two-dimensional templates.
LOGARITHMS
Base-10 logarithm (log) and natural logarithm (ln) with full precision.
40 SCIENTIFIC CONSTANTS
Instantly access 40 fundamental physical constants organized in 5 groups: particle masses, quantum mechanics, electromagnetic, thermodynamic, and universal constants. Constants are displayed with their standard symbols.
ADVANCED MATH FUNCTIONS
• Factorial (x!) for integers 0–69
• Permutation (nPr) and Combination (nCr)
• Absolute value, integer part, fractional part, floor
• Random number (Ran#) and random integer (RanInt#)
• Percentage calculations
MEMORY & VARIABLES
Store and recall values in 26 named variables (A–Z) plus an independent memory register (M) with M+ and M− operations. The last result is always available via Ans.
CALCULATION HISTORY
Browse up to 30 previous calculations. Scroll through history with arrow keys and replay any past expression for quick editing and recalculation.
DISPLAY FORMATS
• Norm — Standard notation with automatic scientific switching
• Fix — Fixed decimal places (0–9 digits)
• Sci — Scientific notation with configurable significant digits
• 15-digit internal precision, 10+2 digit display
PROFESSIONAL PRECISION
15-digit internal cal
Built for university students, engineers, researchers, and professionals who need precision and clarity in every calculation.
NATURAL TEXTBOOK DISPLAY
Enter and view expressions in two-dimensional textbook notation. Fractions, radicals, and exponents are displayed in their true mathematical form — not as flat text. Switch between Natural Display (MathIO) and Linear Display (LineIO) anytime.
EXACT FORM RESULTS
Get results as simplified fractions, square roots, and π expressions — not just decimals. Toggle between exact and decimal forms instantly with S⟷D. The calculator automatically detects when a result can be expressed exactly.
COMPLETE TRIGONOMETRY
All standard and inverse trigonometric functions: sin, cos, tan, sin⁻¹, cos⁻¹, tan⁻¹. Three angle modes: Degrees, Radians, and Gradians. Near-zero results are snapped to exact zero to eliminate floating-point artifacts.
FULL COMPLEX NUMBER SUPPORT
Enter and compute with complex numbers in rectangular (a+bi) or polar (r∠θ) form. Access conjugate, magnitude, argument, real part, and imaginary part functions. Convert between rectangular and polar coordinates with Pol and Rec.
FRACTIONS & MIXED NUMBERS
Work with improper fractions and mixed numbers. Results are automatically reduced. Switch between mixed fraction (a b/c) and improper fraction (d/c) display with one tap.
POWER & ROOT FUNCTIONS
Square, cube root, nth root, arbitrary powers, reciprocal, 10^x, and e^x — all rendered in proper mathematical notation with two-dimensional templates.
LOGARITHMS
Base-10 logarithm (log) and natural logarithm (ln) with full precision.
40 SCIENTIFIC CONSTANTS
Instantly access 40 fundamental physical constants organized in 5 groups: particle masses, quantum mechanics, electromagnetic, thermodynamic, and universal constants. Constants are displayed with their standard symbols.
ADVANCED MATH FUNCTIONS
• Factorial (x!) for integers 0–69
• Permutation (nPr) and Combination (nCr)
• Absolute value, integer part, fractional part, floor
• Random number (Ran#) and random integer (RanInt#)
• Percentage calculations
MEMORY & VARIABLES
Store and recall values in 26 named variables (A–Z) plus an independent memory register (M) with M+ and M− operations. The last result is always available via Ans.
CALCULATION HISTORY
Browse up to 30 previous calculations. Scroll through history with arrow keys and replay any past expression for quick editing and recalculation.
DISPLAY FORMATS
• Norm — Standard notation with automatic scientific switching
• Fix — Fixed decimal places (0–9 digits)
• Sci — Scientific notation with configurable significant digits
• 15-digit internal precision, 10+2 digit display
PROFESSIONAL PRECISION
15-digit internal cal
Latest updates
2.0.9
Minor bugs fixed!
