Paper, desk, supervisor
The Euclid Mathematics Contest is written on paper, in person, under supervision — ten problems, 2.5 hours, 100 marks, with solutions assessed for completeness, clarity, and presentation style. The CEMC’s terms fix the rest — where, when, with which devices, and what happens to results that do not survive scrutiny. This page is the rulebook, condensed.
At the ordering school, and nowhere else
The CEMC’s terms place the sitting precisely: at the school or test centre that ordered the contest, on the official date for the country, “as close to the beginning of the school day as possible” in the school’s time zone. Participants must be supervised in person for the entirety of the writing, and supervisors must keep the work individual — no communication between participants.
That settles a persistent rumour: the Euclid is not an online exam, and any listing describing a camera-proctored, write-from-home sitting is out of date. How a seat is arranged is the registration guide’s business.
A blacklist of capabilities, not brands
One device policy covers all CEMC contests: a calculator is acceptable unless it has any of five capabilities.
The CEMC names three models as explicitly disallowed: the Casio ClassPad 300 series, HP Prime, and TI-Nspire CAS. The ordinary scientific calculator used at school passes.
On full-solution parts a calculator may find the numbers, but the CEMC requires writers to “show the algebraic steps that you used to find these numbers,” adding that specific marks may be allocated for those steps. The machine computes; the marks go to the writing.
The paper’s structure — parts, marks, the difficulty cliff — lives with the competition guide.
Less than you might hope. Only aids indicated on the Contest Question Booklet or the Supervisor Instructions Document may be used while writing — the definitive list travels with the paper itself. In practice: a compliant calculator and what the booklet allows. Nothing that stores, communicates, or draws for you.
The rules behind the results
The consequences are structural, not symbolic. Under the CEMC’s terms, violators are disqualified, dropped from CEMC invitational-workshop consideration, and — the expensive clause — “any current or future offers of admission to the University of Waterloo may be revoked.” Serious cases can see the school banned from CEMC contests in upcoming years, and the CEMC reserves the right to withhold publication of results.
The vigilance is real: the 2024 results booklet restricted international results “due to irregularities,” and test-centre notices in May 2026 described the patterns graders flag — solutions tracking official answers without natural derivation, severe step-skipping, identical scripts, heavy erasures under high scores. That list is the test centres’ reading of CEMC practice, not published CEMC policy.
Appeals travel one road: the writing school or test centre submits the case as a unit — scanned answer sheet, student information card, test paper and scratch-paper copies, proctoring video. No individual appeals are accepted. Honour-roll publication is consent-based — the score-inquiry guide covers results, certificates and consent.
Five questions about the rules
Is the TI-Nspire CAS allowed on the Euclid?
No. The CEMC names the TI-Nspire CAS, HP Prime and Casio ClassPad 300 series as explicitly disallowed, and any device with a computer algebra system fails the policy regardless of model. The safe instrument is the plain scientific calculator used at school.
Can I bring notes or a formula sheet into the contest?
No. Only aids indicated on the Contest Question Booklet or Supervisor Instructions Document may be used, and the device policy separately bans stored information — formulas, programs, notes. What you know must arrive in your head.
Can the Euclid be written online or at home?
No. The contest is paper-based and written at the school or test centre that ordered it, on the official date, with in-person supervision for the entirety of the writing — a camera-proctored, at-home Euclid does not exist in the current terms.
Does calculator output count as shown work?
No. On full-solution parts a calculator may crunch the numbers, but the CEMC requires the algebraic steps used to find them — and notes that specific marks may be allocated for those steps. An unexplained numeric answer forfeits them.
How does a score appeal actually work?
Only through the writing school or test centre, acting as a unit — no individual appeals are accepted. Per the 2026 test-centre notices, schools submit the scanned answer sheet, student information card, test paper and scratch-paper copies, and the proctoring video.