Imported From Malaysia
The Casio FX-991MS / FX-991MS-2 (2-line display) is a non-programmable scientific calculator with quite a lot of useful functions. Here are its main specifications, key features, strengths, and some things to watch out for. If you want I can also compare it against the FX-991EX or FX-570ES PLUS etc.
Key specifications
SpecDetailDisplay2-line (dot matrix top line, numeric bottom line) Digits10 + 2 (10-digit mantissa + 2-digit exponent) Number of functions401 functions Power sourceSolar + battery (dual power) Memory9 variable memories (A–H, etc.) Protective caseComes with a slide-on hard case Size & weightAbout 161.5 × 77 × 11.1 mm, ~ 95 g
Key Features
Fraction calculations; combination & permutation support.
Statistics: includes STAT-data editor, standard deviation, regression etc.
Equation solving; integration/differentiation calculations.
Base-n calculations / conversions (binary, octal, hex etc.)
Complex number calculations
Scientific constants, metric conversion functions
Multi-replay / replay function to revisit and edit previous input / calculations.
Pros & what people like
Two-line display lets you see both what you typed and the result well, making it easier to check for errors.
Has many (but not all) advanced features you would want in science/engineering contexts, especially given its non-graphing nature.
Dual power (solar + battery) helps for battery savings and reliability.
Familiar layout and functionality, especially useful if you're used to older Casio “MS” series calculators.
Limitations / things to consider
Not a “Natural Textbook Display” type (i.e. the kind that shows exponents, fractions etc. exactly how in textbooks). The display is 2 lines, but it's dot-matrix on top and 7-segment / numeric bottom (not full‐textbook style like the FX-991EX or ES/PLUS series) in many cases.
Navigating menus for some functions can be slower since many functions aren’t directly mapped to keys; you may need to shift or go through pages.
Because it’s non-programmable and non-graphing, for very advanced math (symbolic algebra, graph plotting, etc.), you’ll need different tools.
Depending on your exam rules, some features might be restricted; always check what calculators are allowed.
If you want, I can pull up a comparison: FX-991MS-2 vs FX-991EX vs FX-570ES PLUS, so you can see which suits your needs better. Do you want that?
