∫
'23
The 2023 cohort.
First batch to run the full 14-week arc end-to-end. 96% pass, 41 A's.
The Sir · est. 2010 · Colombo
Rajika
Wimalarathne.
Founder of MathDOC X. Educator. Mathematician. Fifteen years, five thousand students, and one teaching rule that has never been relaxed — never board a formula you have not derived.
π
RW
Founder & Lead Lecturer
Since 2010
Colombo · LK
Chapter 01 · founding
2010 — a Saturday class of eleven students in a borrowed hall.
MathDOC began as a weekend theory class for a small batch of A/L students who kept asking the same question in different words: “Sir, where does this formula come from?” The honest answer — that most classrooms never show the derivation — became the founding method. Every result is proved or derived on the board before it is ever used in a tute.
The first rule we ever wrote on the board: never teach a formula you cannot derive from memory, in front of the class, in under five minutes. — Rajika Wimalarathne, founder
Fifteen years later the programme runs island-wide — physical batches in Colombo, a live online cohort, an indexed LMS, and a past-paper archive discussed line by line — but every theory lecture is still delivered by the same person who wrote the first tute in 2010. MathDOC X is, and intends to stay, a one-teacher classroom at its core.
∑
B.Sc · PGDE · 15 yrs
Credentials & standing
Colombo · LK
Record
Credentials &
fifteen years
of cohorts.
- DegreeB.Sc. Special Honours in Mathematics
- PostgradPostgraduate Diploma in Education (PGDE)
- Teaching15+ years · G.C.E A/L Combined Mathematics
- Author“MathDOC” printed revision booklet series
- Cohorts5,000+ students mentored since 2010
- ReachColombo physical batches + island-wide online cohort
0%
Pass rate · 2025 cohort
0+
A grades awarded, 2020–25
0+
Past papers discussed
0
Teacher, start to finish
Batches · 2010 — 2025
Fifteen years
of cohorts.
Every batch since 2010 has left with the same two things: a derived understanding of the syllabus, and a group photo on this wall.
∫
∑
'24
The 2024 cohort.
The first island-wide online cohort ran in parallel with Colombo. 97% pass.
π
'26
The 2026 cohort.
The batch in the room right now — photographed at their new-year gathering, mid-arc.
Principles
Six rules we
refuse to bend.
These are not aspirations — they are the constraints that shape every lecture, tute and mock. Written down in 2015, unchanged since.
01
Derive, never dictate.
Every formula is proved on the board before it appears on a tute. Understanding the why makes the how automatic under exam pressure.
02
Mark-scheme literacy.
We teach how examiners award method marks — structure answers the way they are read.
03
Small on purpose.
Board-side batches stay small. Every monthly paper is marked personally, by hand.
04
Continuity.
The same teacher from the first tute to the final exam. No rotating faculty, no hand-overs.
05
Island-wide parity.
Online students get the identical lecture, tute and feedback cycle as the physical batch.
06
Never teach a shortcut we cannot justify.
Tricks that cannot be proved are tricks that fail under unfamiliar questions. We teach methods that survive any rephrasing the paper attempts — and we say openly when a technique is exam-only.
The support team
One teacher.
A small crew
behind the class.
The Sir delivers every theory lecture. Around him, a small team keeps marking, coordination and the LMS running so nothing falls between batches.
∂
Rajika Wimalarathne
Founder · Lead lecturer
∫
Paper Discussion Lead
Senior assistant · past-paper unit
∑
Batch Coordinator
Enrollment · scheduling · parents
λ
LMS & Digital Lead
Replays · tutes · MathDOC X app
Enrollment · 2026
Learn from the Sir.
Island-wide.
Physical batches in Colombo, live online cohort for everywhere else. Same teacher, same method, same tutes.