Diagnostic-led GCSE maths tutoring in Cardiff. We find out exactly where your child is losing marks, build a four-week plan around it, then measure again so you can see what changed.
Every question we write is built on the new WJEC GCSE Mathematics and Numeracy (Double Award) — first taught in Wales from September 2025. Most tutoring material still follows the specification it replaced.
The problem
Your child's tutor is probably very good. They're also working blind — because a fifteen-year-old genuinely cannot tell you what they don't know.
Not "maths". Not "she says algebra". Specifically what, ranked, and how big the gap is.
The same six measurements, retaken every four weeks. You see what moved, by how much, and what didn't.
Not "past papers". A written plan, aimed at the gaps we measured, that you can read.
The new specification
In September 2025, Wales replaced GCSE Mathematics and GCSE Mathematics–Numeracy with a single new qualification — Mathematics and Numeracy (Double Award). It is worth two GCSEs, it is sat in three separate units rather than one set of finals, and the first results are being awarded now.
Most tutoring material still in circulation was written for the specification it replaced. There are no past papers, because nobody has sat it for long enough to produce any.
Every question in our diagnostic is written against the new specification. Every four-week plan targets it.
Our approach
A four-week cycle, repeated.
Your child sits a short diagnostic at home, built on the WJEC specification. It measures six areas of the course — and separately measures pace, against the time the real exam allows.
Your report arrives at the start of the block, before any teaching happens. Six axes, one per area, so you can see where the gaps are and how large. Not "she struggles with maths" — ratio and proportion at 24, reasoning at 29.
The gaps set the plan. Every session in the block is aimed at a specific measured weakness, and you get the plan in writing — so you know what's being worked on, and why.
Before the next block begins, the same assessment runs again — so every block opens with a fresh report setting the new shape beside the old one. You see exactly what moved, and what the next four weeks will target. When you finish with us, you receive a final closing report.
Every hour is aimed at something we've measured.
The skill map
Toggle between the two assessments to see how a plan shows up in the shape.
The exam allows about 1.3 minutes per mark. The marker shows exam pace. A child who knows the content but works slowly still loses marks — so we measure it separately.
Illustrative example using sample data — not a real student's results.
Why I built this
Nothing left that shop floor without being measured. So why does anyone buy a tutoring hour on a hunch?
I'm Sarah Kuti — a mechanical engineering graduate from Cardiff University, with a placement year at GE Aerospace working on tooling design and quality processes for the GE9X engine programme.
I enjoy teaching because I believe every child deserves to go as far as they can. What engineering gave me is a way of actually doing that rather than just hoping for it: measure first, teach what the measurement points to, then measure again to prove it moved. Tutoring almost never works this way. Families pay for months on faith, and find out whether it worked when the results arrive.
How a session feels matters just as much. Anxiety about maths takes up the very working memory a hard problem needs — so sessions are calm and unhurried, and there's no penalty for not knowing something. Not knowing is the whole reason we're there.
DATUM Learning is that principle applied to GCSE maths. Every child sits a diagnostic built on the new WJEC specification: it scores six areas of the course separately, and measures how fast they work against the time the real exam allows. That produces a map of exactly where the marks are going, and a four-week plan aimed at it — both in writing, before any teaching begins. Four weeks later the same assessment runs again, so you can see what actually moved.
Safeguarding
You're deciding whether to let someone teach your child. Here is exactly what that person has been checked for.
Every DATUM tutor holds an Enhanced DBS check including the Children's Barred List, registered on the Update Service so their status can be re-verified at any time — not a certificate from two years ago.
Two professional references and proof of identity are checked before any tutor works with a student. Safeguarding training is completed during induction.
Sessions happen either at your home or at your tutor's, agreed between you depending on where you both are. Wherever they take place, they're in a room with the door open — never behind a closed one. If we come to you, we ask that an adult is in the house; if you come to us, you're welcome to stay for the session. This protects your child and our tutors equally, and it isn't negotiable.
Sarah Kuti is DATUM's designated safeguarding lead. Any concern raised at hello@datumlearning.co.uk gets a response within 24 hours. Our full safeguarding policy sets out how sessions run, how concerns are raised and exactly what we do about them.
What we offer
You can find out where your child stands without committing to anything — and every tutoring block is booked one at a time.
Find out exactly where your child is, with no commitment to tutoring.
One session a week, with the measurement and planning built in.
For closing bigger gaps, or the run-up to exams.
More than 24 hours' notice — rearrange freely, no charge. Under 24 hours, a £25 charge applies: that is your tutor's fee for the time they set aside, which we still pay them. We don't make a profit on a cancelled session. If your child is genuinely unwell, tell us — we'll usually waive it or arrange a make-up session. Every family also gets two reschedules a term, no explanation needed.
If we or your tutor cancel and can't rearrange within the block, that session is refunded in full.
Questions
The £40 diagnostic is a one-off: your child sits the assessment at home, and you get the written report to keep. It exists so you can find out exactly where they stand without committing to tutoring at all. The blocks are the ongoing service — each one includes its own diagnostic at the start, so the picture is refreshed every four weeks rather than measured once.
Years 9, 10 and 11. Starting in Year 9 or 10 is ideal — there's time to close gaps properly rather than paper over them in the months before an exam.
At the moment, me — Sarah. I'm a Cardiff University mechanical engineering graduate and I teach every session myself. As DATUM grows I'll be bringing on carefully selected tutors, held to the checks set out above.
Not yet — sessions are currently delivered in English. Welsh-medium tutoring is something we're working towards.
We're not ALN specialists, and we won't pretend otherwise. We're very happy to have a conversation about whether we're the right fit — and if we're not, we'll tell you honestly rather than take the booking.
That's your decision, and the reports exist so you can make it on real information rather than a hunch. Progress compounds — a gap closed in Year 10 stops costing marks in every topic that builds on it — so the natural point to work towards is the exam itself. You book a block at a time, so you're never committed more than four weeks ahead.
You'll see it in the report before you see it anywhere else, and we'll say so. Sometimes the answer is a different approach; sometimes it's that the timing isn't right. Our approach only works when everyone's pulling in the same direction — and we'd rather tell you than keep taking your money for a result we can't stand behind.
Maths only. Doing one subject properly, against one specification, is what makes the diagnostic worth anything.