SOF IMO vs SilverZone iOM: which should your Class 6 child take?

If your child is in Class 6 and preparing for a maths olympiad, two names come up more than any other: SOF IMO (International Mathematics Olympiad, run by the Science Olympiad Foundation) and SilverZone iOM (International Olympiad of Mathematics). Both test the same Class 6 NCERT syllabus. They are not the same exam, and the differences affect how a student should prepare.

The short answer

SOF IMO leans harder on logical reasoning (15 of 50 questions) alongside maths, and asks shorter, cleaner-answer questions. SilverZone iOM asks fewer but much heavier questions — 35 for 100 marks, with a big Scholar's Zone weighting — so a single wrong answer costs far more. What iOM does not give is thinking time: 35 questions in 40 minutes is about 69 seconds each, against about 72 seconds each for IMO's 50 in 60 minutes. iOM is the tighter paper of the two, not the roomier one. Many schools run both, since the registration windows rarely clash and the syllabus overlap means very little extra preparation is needed for the second exam.

How do the SOF IMO and SilverZone iOM papers differ?

In three ways that matter to a Class 6 child: IMO asks 50 light questions and iOM asks 35 heavy ones, IMO spends a quarter of its marks on logical reasoning (15 of 60) while iOM spends under a fifth on reasoning and aptitude (17.5 of 100), and iOM leaves slightly less time per question despite being the shorter paper. Neither exam deducts marks for a wrong answer, so on both papers every question is worth attempting.

• SOF IMO (Class 6): 50 questions, 60 marks, 60 minutes. Sections: Logical Reasoning (15 questions), Mathematical Reasoning (20 questions), Everyday Mathematics (10 questions), Achievers (5 questions, 3 marks each). No negative marking.
• SilverZone iOM (Class 6): 35 questions, 100 marks, 40 minutes. Sections: Mathematics (25 questions, 2.5 marks each), Reasoning & Aptitude (5 questions, 3.5 marks each), Scholar's Zone (5 questions, 4 marks each). No negative marking.
• Both draw roughly 60% of questions from the current-year (Class 6) syllabus and the remainder from Class 5, so a student who has only just started Class 6 is not at a disadvantage in August–September.

How much of the syllabus do the two exams share?

Both exams draw from the same ten Class 6 NCERT Ganita Prakash chapters — Patterns in Mathematics, Lines and Angles, Number Play, Data Handling and Presentation, Prime Time, Perimeter and Area, Fractions, Playing with Constructions, Symmetry, and The Other Side of Zero. A student preparing seriously for one exam is already 90% prepared for the other; the remaining gap is exam-specific reasoning style, not new content.

So which one should you pick?

If your child's school offers only one, take it — the syllabus overlap means neither is "wasted" preparation for the other. If both are offered and your child has time for two exam days, SOF IMO is the better first exam for a child still building speed under logical-reasoning-style questions, and SilverZone iOM rewards a child who thinks carefully through fewer, denser problems. Neither exam requires coaching beyond a genuinely strong grip on the NCERT syllabus plus olympiad-pattern practice — which is exactly the gap OlympAI's olympiad-pattern practice is built to close, at up to 200 practice questions a day per subject.