# Scientific Calculator Casio FX-991DE X Desktop Black

**URL:** https://aio.lv/en/product--casio-fx-991dex--631557
**Data updated:** 2026-01-13 15:26 (EET)
**Category:** Calculators
**Manufacturer:** CASIO
**Manufacturer code:** FX-991DEX
**EAN:** 4971850093657
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 49.49 €
**Prices and availability valid until:** 2026-07-09 23:59
**Price without VAT (21%):** 40.90 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--casio-fx-991dex--631557

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 09.07.2026 | free |
| Pickup points | 14.07.2026 | 1.99 EUR |
| Courier delivery to door | 14.07.2026 | 4.99 EUR |

## Summary description

The Casio FX-991DE X is a desktop scientific calculator featuring a dual power source (battery and solar). It offers a wide range of functions, including advanced calculations for algebra, calculus, and statistics. The sleek black design makes it a stylish addition to any workspace. Ideal for students and professionals alike, it provides reliable performance and user-friendly operation.

## Long description

The Casio FX-991DE X Desktop Black is a scientific desktop calculator designed for advanced mathematical, engineering and statistical work. It combines battery and solar dual power for reliable operation and offers a broad set of functions for algebra, calculus and statistics in a compact, black housing intended for desktop use. The calculator supports precise numeric entry, multi-line display viewing and a menu structure adapted for academic and professional tasks.
Advantages
The device provides dual power (battery and solar) to reduce unexpected shutdowns and prolong service life. Its function set covers a wide range of calculations including algebraic expressions, derivatives, integrals and statistical analysis, enabling complex problem solving without external software. The desktop form factor gives a stable working surface and a clear, easy-to-read display layout for continuous use.
Suitable for
High school and university mathematics and physics exercises
Engineering calculations and technical studies
Statistical analysis and data processing tasks
Classroom use, exam preparation and desktop reference
Key specifications
Power: dual power source (battery and solar)
Functions: algebra, calculus (derivatives and integrals), statistics, fractions and complex numbers
Display: multi-line display for expression entry and result review
Form factor: desktop model with stable base and full-size keys
Design: black casing suitable for professional environments
How to use
Place the calculator on a stable, well-lit desktop surface. Power is managed automatically between solar input and battery; ensure the solar panel receives sufficient light for optimal operation. Enter expressions using the multi-line display to review complex formulas before confirming calculations. Use the mode and function keys to switch between calculation types (e.g., algebraic, calculus, statistical) and follow on-screen prompts for parameter input. For series of calculations, clear the entry or use the memory functions as appropriate.
Usage recommendations
Keep the calculator in moderate lighting to maintain solar charging and replace the battery according to the manufacturer’s guidance if power becomes unreliable. For exam or classroom use, verify allowed device models with the institution. Clean the keys and casing with a soft, dry cloth and avoid exposure to excessive heat or moisture to preserve functionality.

## Specifications

| Feature | Value |
|---|---|
| Type | Scientific |
| Weight | 0.09 kg |
| Form factor | Desktop |
| Battery type | LR44 |
| Number of batteries supported | 1 |
| Power source | Battery/Solar |
| Height | 11.1 mm |
| Display resolution | 192 x 63 |
| Width | 77 mm |
| Depth | 165.5 mm |
| Backlight display | No |
| Product colour | Black |
| Control type | Buttons |
| Second display | No |
| Display tilting | No |
| Display type | Dot-matrix |
| Keys quantity | 50 keys |
| Cover | Yes |

## FAQ

### How much does the Scientific Calculator Casio FX-991DE X cost, and is it available for purchase?

The price is 49.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 101 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 09.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All CASIO products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized CASIO service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

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