The Singapore Mathematical Olympiad (SMO) is organised by the Singapore Mathematical Society. SMS states that it has organised national mathematical competitions since the 1950s and that the current name Singapore Mathematical Olympiad has been used since 2001. The competition is designed to test ingenuity and mathematical problem-solving ability and to discover and encourage mathematical talent.
SMO has three routes: Junior, Senior and Open. They should not be treated as the same paper at different ages. The eligibility, mathematical depth and second-round proof demands change substantially across the sections.
SMO Junior
For 2026, Junior is open to eligible Secondary 1 and Secondary 2 students. Round 1 is a two-and-a-half-hour written paper with multiple-choice and short questions. The top 10% of Round 1 are invited to Round 2, a three-hour written paper requiring full-length solutions.
SMO Senior
For 2026, Senior is open to eligible Secondary 3 and Secondary 4 students. Round 1 is again two and a half hours with multiple-choice and short questions. The top 10% progress to a four-hour Round 2 requiring full-length solutions.
SMO Open
The 2026 Open section is available to eligible full-time students from Secondary 1 through Secondary 4 and Junior College who have not attended a tertiary institution full-time. Round 1 is a two-and-a-half-hour written paper of short questions. Selected participants enter a four-hour Round 2 of full-length solutions. SMS states that Open Round 2 results are a key criterion for selection of the Singapore National Training Team for the International Olympiad in the following year.
The real transition: answers → proofs
The deepest transition in SMO preparation is not simply harder arithmetic. It is the move from obtaining an answer to constructing a complete mathematical argument. A learner may have the right idea but still need to justify exhaustiveness, handle cases, state conditions and show why each step follows.
Core domains
- Number theory: divisibility, modular structure, integer equations.
- Combinatorics: counting, pigeonhole, invariants, extremal reasoning.
- Geometry: configuration reading, similarity, circles, auxiliary constructions.
- Algebra: identities, polynomials, inequalities, functional relationships.
- Proof: contradiction, induction, construction, case completeness and rigorous explanation.
A staged preparation route
- School Mathematics reliability. Routine algebra, geometry and number work should not consume excessive working memory.
- Non-routine problem solving. Train representation, experimentation and strategic search.
- Domain depth. Build number theory, combinatorics, geometry and algebra beyond the school chapter sequence.
- Proof writing. Learn to turn insight into a complete argument.
- Long-problem endurance. Practise staying with a difficult problem without immediately seeking a hint.
Where to go next
- Mathematics Olympiad & Competition Hub
- Secondary Mathematics Learning Hub
- Additional Mathematics Synthesis Guides
- Mathematical Lab
Frequently asked questions
Is Round 2 just a harder Round 1?
No. The published rules show a major format shift: later rounds require full-length solutions, which makes proof communication and completeness much more important.
Does Open feed into international olympiad selection?
For 2026, SMS states that Open Round 2 results are a key criterion in selecting the Singapore National Training Team for the International Olympiad in the following year.
Official source checked 26 September 2026: Singapore Mathematical Society SMO and the 2026 Junior, Senior and Open rules. Eligibility and timings are year-specific.
World Mathematics route: return to the World Mathematics Atlas for the wider map across competitions, school Mathematics, examinations, mathematical objects and university routes.