Thales
The first phase of Greece's secondary school math competition pipeline (grades 7-12). Open to all students, with top performers qualifying for Euclid. Proof-based format requiring full written solutions.
Grade Levels
Grades 7-12 (Ages 12-18)
Format
Proof-Based · 5 questions · 2.5-3 hours
Scoring
Each problem scored out of 10 points. Partial credit awarded for progress toward solutions.
Participants
30,000-50,000+
October
Registration through schools (early October)
October
Competition held late October to mid-November
Registration
Schools register students through local EME branches
Prizes & Recognition
Certificates for all participants. Top scorers (~20-30%) qualify for the Euclid competition.
About This Competition
The Thales Mathematical Competition (Μαθηματικός Διαγωνισμός «Θαλής») is the first and broadest stage of the Hellenic Mathematical Society's secondary school competition pipeline. Named after Thales of Miletus (c. 624-546 BC), considered the first Greek mathematician, this competition opens the door to advanced mathematical reasoning for gymnasium and lyceum students.
Unlike the Pythagoras competition (which tests mathematical thinking through multiple-choice questions), Thales requires students to provide full written solutions and proofs. Each grade level receives a separate paper with 4-5 problems, and partial credit is awarded for progress toward solutions. The competition tests not just mathematical knowledge but the ability to construct logical arguments.
With 30,000-50,000+ participants, Thales represents the largest pool of secondary school mathematicians in Greece. The top 20-30% of scorers advance to the Euclid competition in January.
How to Prepare
Master Proof Writing Fundamentals
Thales requires written proofs. Practice structuring proofs with clear logical steps: state what you know, what you need to prove, and build your argument methodically.
Start with What You Can Solve
Read all problems first and begin with the ones you find most accessible. A complete solution to an easier problem scores more than an incomplete attempt at a harder one.
Study EME's Problem Archive
Past Thales problems and model solutions are published by EME. Compare your proof style with the official solutions to learn better techniques.
Thales Is the Gateway to Euclid
Strong performance in Thales qualifies you for the Euclid round. Use this as motivation but don't let the pressure overshadow the joy of problem-solving.
Strengthen Geometry and Algebra Equally
Thales covers both geometry and algebra. Ensure you practice problems from both domains, as students often neglect one area in favor of the other.
Frequently Asked Questions
What is the Thales competition?
Thales is the first phase of the EME secondary school mathematics competition pipeline in Greece. It is open to all gymnasium (grades 7-9) and lyceum (grades 10-12) students and serves as the broadest qualifying stage.
How does Thales differ from Pythagoras?
Pythagoras targets students in grades 2-9 with multiple-choice problems testing mathematical thinking skills. Thales targets secondary students (grades 7-12) with proof-based problems requiring full written solutions. While Pythagoras covers gymnasium grades too, it focuses on reasoning skills rather than advanced proofs.
What happens if my child does well in Thales?
Top performers (approximately the top 20-30% of scorers) qualify for the Euclid competition, the second phase of the EME pipeline.
Related Competitions
Pythagoras
The Hellenic Mathematical Society's math skills competition for students in grades 2-9 (elementary and gymnasium). Features 20 multiple-choice questions testing mathematical reasoning, not rote knowledge. Held annually on a single Saturday in March.
Kangourou Greece
The Greek chapter of Math Kangaroo, the world's largest mathematics competition. Open to all grades 1-12 with multiple-choice format and emphasis on making mathematics fun and engaging.
Euclid
The second phase of Greece's EME competition pipeline. By invitation only for top Thales performers. More challenging proof-based problems requiring sophisticated mathematical reasoning.
Archimedes
The third and final qualifying stage of Greece's EME pipeline before the National Olympiad. Olympiad-level proof problems for top performers from Euclid.
Greek Mathematical Olympiad
Greece's national mathematical olympiad, the final selection stage for the IMO team. By invitation only for top Archimedes performers. IMO-style format with 6 problems over 2 days.
Balkan Mathematical Olympiad
Regional olympiad for Balkan countries including Greece, Romania, Bulgaria, and Cyprus. Important stepping stone toward IMO for participating nations.