The Casio fx-991CW can tell you whether it’s genuine before you hand over any money. Press HOME, open Settings, and the calculator shows a QR code that, once scanned with your phone, opens Casio’s own page with one of two results, “Likely to be a genuine product” or “Is not a genuine product”, according to Casio’s authenticity check page as of November 2, 2026. That takes less than a minute at the shop counter, and it matters this week because NECO’s SSCE External starts on Wednesday, November 4.
NECO’s timetable for the exam states that the “use of scientific calculator is allowed”, while programmable calculators sit on its list of banned gadgets alongside phones, tablets and smartwatches. So a candidate buying a calculator now needs two things from it, a model that’s allowed in the hall and a unit that won’t fail halfway through a paper. Casio’s QR check helps with the second, and the fx-991CW’s own specifications settle the first.
| Type | Non-programmable, non-graphing scientific calculator |
|---|---|
| Functions | 540+ functions |
| Display | High-definition, four-tone screen with Natural Textbook Display |
| Power | Solar with battery backup, about 2 years of main battery life |
| Equation solver | Up to 4 unknowns, matrices up to 4x4 |
| Spreadsheet | 5 columns by 45 rows |
| Size | 162 x 77 x 10.7mm |
| Weight | 95g |
The QR test takes a few presses on a genuine Casio fx-991CW
On the fx-991CW, press HOME, then go to Settings to bring up the QR code. Scan it with your phone’s camera and Casio’s ClassWiz services page opens, showing a 20-digit Calculator ID whose first four characters are the model number. Scroll down that page and the authenticity result appears. If the model number in the ID doesn’t match the calculator in your hand, treat that as a warning on its own.
Casio uses different key presses on older models, and the official authenticity page lists them. On the fx-991EX and fx-570EX, press ON, MENU, SHIFT, then OPTN, and Casio says that if your phone can’t read the code, the calculator “may possibly be a counterfeit model”. On the fx-ES PLUS 2nd edition, press ON, MODE, then 0, and tap Check on the page that opens.
The box carries a second check that sellers can’t easily fake
Boxes with Casio’s hologram sticker give you another test before the seal is even broken. Casio says the hologram on a genuine sticker changes colour as you tilt it left and right, and the shading reverses when you rotate it. The sticker also has its own QR code, and scanning it returns “Likely to be a genuine product”, “May not be a genuine product” or “Is not a genuine product. Please do not purchase it.” If the scan simply opens Casio’s regular website with no result, Casio’s instruction is plain, “it is NOT a genuine product. Do not purchase it.”
Casio is careful to add that the check “does not necessarily guarantee that the product is genuine”, so a pass lowers the risk rather than removing it. Buying from a seller who will let you run both checks before payment, and who’ll take the calculator back if the result is wrong, protects you far better than a low price does. We use the same approach in our guide to spotting an original Oraimo product, and the lesson from the Ledger spy chip case applies here too, since a convincing box isn’t proof of what’s inside it.
A fake can let you down where it hurts most, in the exam hall
Casio’s own comparison explains why the check is worth a minute of your time. It says counterfeit units may have faulty wiring or a solar cell that’s there only for show, may use more power or take a non-standard battery, and may skip the aluminium back panel that sits behind a genuine display. A calculator that dims or freezes during NECO’s General Mathematics objective paper, which runs for an hour and 45 minutes, costs you time you can’t get back.
The fx-991CW itself fits NECO’s rule, because Casio’s US product page lists it as non-programmable and non-graphing, and Casio’s Nigerian education site covers its equation solver, matrices and statistics modes. Its battery backup also means it keeps working when the solar panel isn’t getting enough light. Check the rules for any other exam you’re writing, since each exam body sets its own list of what candidates may bring into the hall.
Before you pay, ask the seller to switch the calculator on in front of you, then run the QR check on the unit and on the box sticker, and buy only when both come back as likely genuine. If you already own a Casio, run the same check today, so there’s still time to replace a failed unit before NECO’s first paper on Wednesday.
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