fx-991 CW


For a limited time only, get 20% off with promotional code CALCU20

The Casio fx-991 CW ClassWiz is the new upgraded version of the Casio fx-991 EX (Casio’s most advanced scientific calculator), containing additional features, to include a high definition display and improved menu navigation. Approved for Key stages 3, 4 and 5, recommended for Advanced GCSE, A/AS level and Highers. Allowed in every UK exam where a calculator can be used. 

The large Natural Textbook Display shows mathematical expressions like roots and fractions as they appear in your textbooks which increases comprehension because results are easier to understand.

  • Clip-on on protective hard cover included
  • 540+ functions
  • Dual powered, solar with battery backup and Auto power-off.
  • Free 3 year guarantee included
  • Free UK delivery 
  • View our Model Comparison Chart to find the right calculator for you                                                                                                                                          
Other models to consider:               
 If you require an even more powerful and more advanced calculator, the Casio Graphic calculator range provides dynamic graphing; capable of calculating and displaying graphs, charts, spreadsheets and statistics.Casio Graphic range includes the fx-9860GIII and fx-CG50

In stock


Klarna available


Standard Delivery in 2-4 working days-  £2.95 (Free for orders over £50)
Express Delivery in 1-2- working days- £5.00

Click & Collect

Going to be out? Have your delivery safely sent to a local store for collection


All of our products come with at least 2 years warranty



Mainland UK
Standard: 2-4 Business days after dispatch £2.95 (Free for orders over £50)
Express: 1-2 Business days after dispatch £5.00
(Express delivery only available for orders placed before 2.30pm – Excluding weekends & Bank Holidays)

Republic of Ireland & Channel Islands
Standard: 4-5 Business days after dispatch
Express: Not Available

Our nominated carrier is Parcel Force. Deliveries are made Monday – Friday between 9.00am – 6.00pm (excluding Bank Holidays).
If you require any further information relating to the Delivery service used, please call us at +44 (0)20 8208 9567.


If for any reason you change your mind or are not satisfied with your purchase, please return your purchase to Casio within 28 days of purchase. Please note that with the exception of faulty products, we cannot accept the return of items, which have been opened or used. This does not affect your statutory rights.

The below process should be followed:

1 - Complete the short form that accompanies your product. Please ensure that you complete all of the sections, as this will guarantee the timely processing of your return/exchange.

2 - Place your item in the original packaging along with the form. Please ensure that the product is pristine with all original manuals and tags.

3 - Send the box to us using a recorded/signed & trackable service to the address below. Please note, we cannot be held responsible for a package that has not been received by us.

4 - Return Address

Yusen Logistics Co Ltd
Casio Returns - Bay 32
Bradbourne Drive
Milton Keynes

Tel:+44(0)20 8208 9452
Email: collections@casio.co.uk

5 - Retain your tracking details, until you receive notification from Casio that your returned product has been safely received. Once received and processed, it may take up to 5-7 business days for your refund to be displayed on your payment card statement.