Which Casio Scientific Calculator Should You Buy? FX-991 Guide for Sri Lanka

Short answer: For most O/L and A/L students in Sri Lanka, the Casio FX-991ES Plus (2nd Edition) is the practical pick — it’s non-programmable (so it’s accepted in exams), uses Casio’s Natural Textbook Display, and costs Rs. 5,900. If you want the newest model with a sharper screen and more functions, choose the FX-991CW (Rs. 7,800). If you’re on a tighter budget, the older FX-991MS (Rs. 5,800) or FX-100MS (Rs. 4,800) still cover the full O/L and A/L syllabus. All of them are non-programmable, so all are exam-safe.

Every model below is a non-programmable scientific calculator, which is the category Sri Lanka’s Department of Examinations permits for G.C.E. O/L and A/L. Always confirm the current year’s rules with your exam board before the exam.

Quick comparison

How to Choose a Casio Scientific Calculator

Picking the right Casio scientific calculator comes down to three questions: Will you use it in an exam? Which display type do you prefer? And what is your budget? The sections below walk through each.

Going by exam: O/L and A/L

The thing that matters most for an exam is that the calculator is non-programmable. Every FX-991 model and the FX-100MS in the table above is non-programmable, so any of them is a safe choice for G.C.E. O/L and A/L. The differences between them are about screen quality, speed, and extra functions — not about whether you’re allowed to use them. (Confirm the current rules with the Department of Examinations, Sri Lanka for your exam year.)

Going by display

• Natural Textbook / ClassWiz display (FX-991ES Plus, FX-991EX, FX-991CW) shows fractions, surds, and integrals the way they’re written in your textbook. This is the single biggest day-to-day quality-of-life difference, and it reduces input mistakes.
• 2-line display (FX-991MS, FX-100MS) is the older style — it works perfectly well and covers the same maths, but it doesn’t render expressions in textbook form.

Going by generation

Casio’s “ClassWiz” line (FX-991EX and the newer FX-991CW) has a higher-resolution screen, a faster processor, and more built-in functions than the older ES Plus and MS series. The FX-991CW is the most recent model and uses a redesigned menu-based interface; if you’re buying new and want the longest useful life, it’s the forward-looking choice.

Going by budget

The FX-100MS (Rs. 4,800) is the lowest-cost way to get a full scientific calculator that covers the syllabus. Step up to the FX-991ES Plus (Rs. 5,900) for the Natural Textbook Display, which most students find worth the difference.

Not for exams? Desktop calculators for office use

If you’re doing accounts or counter work rather than maths exams, a desktop calculator is the right tool — not a Casio scientific calculator. Here are the desktop models we stock:

• Casio MJ-120D — Rs. 2,500 — 12-digit, check-and-correct, everyday desk use.
• Casio DJ-120D — Rs. 3,600 — 12-digit with a 300-step check function, for heavier accounting work.

Buy Casio Scientific Calculators from officestationery.lk

We stock a wide range of Casio scientific calculators — every model in the comparison above and more — at our store at 303/2 R. A. De Mel Mawatha, Colombo 00300. Most orders dispatch in 1–3 days via PickMe, Koombiyo, or Prompt XPress — shipping is set by the courier and shown at checkout, or you can pick up in-store at no extra cost. Need a Casio scientific calculator in bulk for a school or institution? We have wholesale pricing — call 071 888 1111.

Frequently asked questions

Whether you are buying your first Casio scientific calculator for O/L exams or upgrading to the latest ClassWiz model, all the options above are stocked and available at officestationery.lk. Every Casio scientific calculator we sell is genuine, comes with a local warranty, and can be ordered online or collected in-store.