Short answer: The best calculator for GCSE maths is one that's allowed in the exam, has the functions the course needs, and that the student is comfortable using. Both of these qualify. The Casio fx-83GT CW is the market-standard calculator. It has more functions (290+) and a Natural Textbook Display that shows fractions and roots the way they look in a textbook. The KAPEK Mathematics Set is the better all-in-one buy. For £14.99 you get a scientific calculator plus a full geometry set, a case and a built-in clock, in Blue, Pink or Black, with free UK delivery. The KAPEK calculator is Permitted in GCSE exams, and the set is suitable from KS3 to A-level. Want the most calculator for the money? Go for the Casio. Want everything for maths lessons in one case? Go for KAPEK.
What are you comparing?
The two products aren't quite the same kind of thing, and that matters when you compare prices.
- The Casio fx-83GT CW is a calculator on its own. It's part of Casio's ClassWiz range and is the upgraded version of the fx-83GT X. Casio describes the fx-83 as the UK's best-selling scientific calculator. Casio also sells an updated fx-83GT CW+, which has the same 290 functions and a few extra menu shortcuts.
- The KAPEK Mathematics Set is a complete maths kit: a sturdy EVA case (26.5 cm × 12.3 cm) holding a detachable scientific calculator and a full geometry set (compass, protractor, rulers and more). It also has a built-in 24-hour digital clock and a slide-on protective fascia.
So the Casio is a calculator. KAPEK is a calculator plus everything else on a GCSE Maths paper's "You must have" list.
What GCSE students need from a calculator (JCQ rules)
The Joint Council for Qualifications (JCQ) sets the rules for calculators in GCSE exams. Here's a summary of the JCQ Instructions for Conducting Examinations 2025–26 (section 10) and the JCQ calculator FAQs:
- It must be a calculator. Its main purpose has to be maths calculations, so a phone with a calculator app can't be used.
- No banned features. During the exam it must not offer language translation, symbolic algebra, symbolic differentiation or integration, or any connection to other devices or the internet.
- No stored information. It must not give access to anything stored before the exam, such as databanks, dictionaries, formulae or text. Built-in scientific constants are allowed.
- Students are responsible. It's up to the student to make sure their calculator follows the rules, and they can't borrow one from another student during the exam.
The JCQ information for candidates (2025–26) also says to check the batteries, clear the memory, and take off any case, lid or cover that has instructions or formulae printed on it. Watches aren't allowed in the exam room, and any pencil case must be see-through.
Exam-day tip: if you use a KAPEK set, detach the calculator and take it in a clear pencil case, with your compass, protractor and ruler. Leave the case, which has a built-in clock, outside the room. Whichever calculator you use, check with your teacher or exams officer that it's allowed for your exam. Our GCSE Maths equipment checklist covers the full list.
Beyond the rules, GCSE maths uses trigonometry, powers and roots, fractions, percentages, standard form and statistics. A two-line or textbook-style display helps, because you can see your working and the answer together.
Side-by-side comparison
| Feature | KAPEK Mathematics Set | Casio fx-83GT CW |
|---|---|---|
| What's included | Scientific calculator + full geometry set (compass, protractor, rulers etc.) in a case | Calculator with clip-on hard cover |
| Calculator functions | 240+ | 290+ |
| Display | Two-line LCD (input and answer shown together) | Natural Textbook Display (high definition) |
| Fractions | Yes | Yes, shown in textbook format |
| Memory | 9 variable memories, multi-replay | Variables list, expression editing |
| Extras | Built-in 24-hour digital clock, detachable calculator, slide-on fascia | QR code for graph display, "Maths Box" dice/coin simulations, prime factorisation, HCF/LCM |
| GCSE exams | Permitted in GCSE exams (meets JCQ calculator rules) | Casio says it's allowed in every UK exam where a calculator can be used |
| Colours | Blue, Pink, Black | Black, Blue, Grey, Pink |
| Power | See product page | 1 × AAA battery (supplied), auto power-off |
| Levels | KS3 to A-level (for A-level, check what your course asks for) | Key Stages 3 & 4: GCSE, National & Higher, Junior & Leaving |
| Price | £14.99 (calculator and geometry set) | £16.49 from Casio UK; retailers from about £12 |
| Delivery, returns and guarantee | Free UK delivery, dispatch within 2 business days, 30-day returns (customer pays return postage) | 3-year Casio guarantee |
| Customer rating | About 4.8★ on kapek.net (100+ reviews per colour); 4.4★ on Amazon | Not compared here |
Casio details come from Casio UK and Casio Education. Retailer prices were checked on idealo in October 2026 and change often.
Where the Casio fx-83GT CW wins
To be fair, the Casio is the calculator many UK maths teachers expect to see, and there are good reasons for that.
- Natural Textbook Display. Fractions, roots and powers appear as they do in a textbook. That helps students check they've typed a calculation correctly.
- More functions. Casio lists 290+ functions, including statistics with regression, tables of values, equivalent ratio, prime factorisation, HCF and LCM.
- Classroom familiarity. Because the fx-83 is so widespread, teachers often demonstrate key presses on a Casio. If your child's class uses one, matching it can make lessons a little easier.
- Long guarantee. Casio includes a free 3-year guarantee.
Where the KAPEK Mathematics Set wins
KAPEK's strength is value and convenience.
- The geometry set is included. GCSE Maths papers list a ruler, protractor and pair of compasses as required equipment. Buy a Casio and you still need to buy those separately. With KAPEK, they come in the case.
- Everything stays together. The calculator and tools live in one case, so it's harder to lose the compass the night before a test. The calculator detaches, so you can use it on its own.
- Lower price for the whole kit. At £14.99 with free UK delivery, the full KAPEK set costs less than Casio's list price of £16.49 for the calculator alone.
- Handy features. A two-line display, 9 variable memories and a built-in clock for timing revision sessions and past papers at home.
- Colour choice. Blue, Pink or Black. That makes it a good gift and easy to tell apart from a classmate's.
- Well reviewed. Every colour on kapek.net averages around 4.8 stars from 100+ reviews.
KAPEK was established in 2015 and says it has sold over 15 million sets worldwide.
Who each one suits
Choose the Casio fx-83GT CW if:
- your school or teacher asks for that exact model, so the student can follow the teacher's examples
- you already own a geometry set and only need a calculator
- you want the textbook-style display, the extra functions and the 3-year guarantee
Choose the KAPEK Mathematics Set if:
- you're starting secondary school or GCSEs from scratch and need the calculator and the geometry tools for constructions, angles and shapes in one go
- you'd like everything in one sturdy case that's harder to lose in a school bag
- you're buying on a budget, or looking for a practical Christmas gift for a student
Being honest: if a teacher builds lessons around a particular Casio model, using that model can make lessons a little easier. If you're buying for A-level maths, check the course's calculator requirements with the school first. Casio positions the fx-83GT CW for Key Stages 3 and 4 and recommends its more advanced fx-991CW for A/AS Level. Plenty of families end up with both: KAPEK as the everyday kit for lessons and homework, and a second calculator as a spare.
Shop the KAPEK Mathematics Set
- KAPEK Mathematics Set – Blue (£14.99)
- KAPEK Mathematics Set – Pink (£14.99)
- KAPEK Mathematics Set – Black (£14.99)
Every set comes with free UK delivery and is dispatched within 2 business days. There are 30-day returns, and the customer pays return postage. Ordering for Christmas? Order by Friday 18 December. Got a question? See our FAQ page.
Frequently asked questions
What is the best calculator for GCSE maths?
The best calculator for GCSE maths is one that's allowed in the exam and that the student knows how to use. The Casio fx-83GT CW is a popular school choice with 290+ functions. The KAPEK Mathematics Set suits students who also need a geometry set: you get the calculator, compass, protractor and rulers in one set for £14.99 with free UK delivery.
Is the KAPEK calculator allowed in GCSE exams?
Yes. The KAPEK scientific calculator is Permitted in GCSE exams, and it meets JCQ calculator rules. Before each exam, clear its memory. Detach the calculator and leave the case, which has a clock, outside the room, because watches aren't allowed. The Casio fx-83GT CW is also allowed: Casio says it can be used in every UK exam where a calculator is permitted.
What calculators are not allowed in GCSE exams?
Under JCQ rules, you can't use phones or other devices that aren't mainly calculators. Calculators that offer language translation, symbolic algebra, symbolic differentiation or integration, or connections to the internet or other devices aren't allowed either, and nor are calculators that give access to stored formulae or text during the exam.
Can the KAPEK calculator do fractions?
Yes, the KAPEK calculator handles fraction calculations. It uses a two-line display rather than the Casio's textbook-style display.
Is a scientific calculator for school useful before GCSE, and what about A-level?
Yes. Students who start using a scientific calculator in KS3 have time to get used to it before their exams. The KAPEK Mathematics Set is suitable from KS3 to A-level, but A-level students should check their course's calculator requirements. Casio recommends its more advanced fx-991CW for A/AS Level.
How fast does KAPEK deliver, and what's the Christmas cut-off?
Orders are dispatched within 2 business days, and UK delivery is free. To get your order for Christmas, order by Friday 18 December. There are 30-day returns, and the customer pays return postage.