SOF IMO vs SilverZone iOM: Classes 7 and 8 compared

If your child is in Class 7 or Class 8 and two maths olympiad names keep coming up — SOF IMO, run by the Science Olympiad Foundation, and SilverZone iOM — most of the advice you will find online compares them at Class 6 and leaves you to assume the comparison carries upward. It carries for one of them and not the other. SOF IMO is the same paper at Classes 6, 7 and 8. SilverZone iOM changes shape between Class 6 and Class 7, and the change is large enough to alter how a child should prepare.

Does the paper change between Class 6, 7 and 8?

For SOF IMO, no. At Class 6, Class 7 and Class 8 it is 50 questions for 60 marks in 60 minutes, split the same way every time: Logical Reasoning 15 questions, Mathematical Reasoning 20, Everyday Mathematics 10, and an Achievers Section of 5 questions worth 3 marks each. Only the syllabus moves up a year. For SilverZone iOM, yes — and in a specific place. The paper stays 35 questions for 100 marks in 40 minutes, but at Class 6 the named maths section carries 25 of those questions, while at Class 7 and Class 8 the named syllabus sections carry only 20 between them. The 5 questions that move go to Reasoning and Aptitude, which grows from 5 questions to 10.

How much of SilverZone iOM is actually syllabus maths?

Half of it, at Class 7 and Class 8. The named topic sections — Number Systems, Algebra, Geometry and Mensuration, Comparing Quantities, Data Handling and so on — account for 20 of the 35 questions and 50 of the 100 marks. The other 50 marks come from 15 questions: 10 of Reasoning and Aptitude at 3 marks each, and 5 Scholar’s Zone questions at 4 marks each. At Class 6 the same two sections are worth 37.5 marks from 10 questions, so the load outside the syllabus sections rises by 12.5 marks and 5 questions when a child moves from Class 6 to Class 7. SOF IMO has no equivalent jump: its Logical Reasoning section is 15 questions and 15 marks at every one of the three classes.

One more figure worth having before you plan revision. At Class 8, Mensuration is the thinnest section on the iOM paper — 2 questions, 5 marks — which is worth knowing before spending a fortnight on surface areas and volumes.

Which paper gives a child more time to think?

Neither, and if anything it is IMO by a hair. It is easy to read “35 questions in 40 minutes” against “50 questions in 60 minutes” and conclude that the shorter paper is the calmer one. The arithmetic says otherwise: 40 minutes over 35 questions is about 69 seconds each, and 60 minutes over 50 questions is about 72 seconds. What differs is not pace but consequence. On IMO most questions are worth 1 mark of 60, so a dropped question costs under 2 per cent of the paper. On iOM a Scholar’s Zone question is worth 4 marks of 100, so a single one costs more than twice as much. iOM is the paper where accuracy pays and a stall is expensive; IMO is the paper where steady coverage pays.

Which one should a Class 7 or Class 8 child take?

In practice the school usually decides, because both of these are entered through the school by default rather than by a parent. Where a school offers both and there is time for two exam days, the honest split is this: a child whose maths is strong but who is still slow on verbal and non-verbal reasoning will find a larger share of iOM sitting outside the chapters they have revised, and should treat reasoning as a subject rather than a warm-up. A child who is comfortable with reasoning and wants the widest coverage of the syllabus itself will get more out of IMO, where 30 of the 50 questions come straight from the named maths sections. Neither exam is a harder version of the other, and neither is wasted preparation for the other — the syllabus underneath both is the same Ganita Prakash book for the class.

When does registration close for each?

The two bodies answer this differently, and the difference matters more than either date. SOF publishes no last date at all — it publishes a rule, in its own words: “Schools may send registrations by 30 days before the chosen date of each exam.” So IMO’s cutoff depends on which sitting your school picks. If your school picks 23 October 2026, registrations reach SOF by 23 September 2026; if your school picks 26 November 2026, by 27 October 2026; if your school picks 10 December 2026, by 10 November 2026. SOF also states that “change of date is not permitted”, so once the school has chosen, that cutoff is fixed. SilverZone does the opposite: it publishes one date, 30 September 2026, covering every paper it runs, against iOM sittings of 8 October, 18 November and 7 December 2026.

Both of those dates bind your school rather than you. The useful thing a parent can do with either is ask the school coordinator one question — which sitting have you picked for this paper — because until that is answered, neither cutoff can be worked out. SilverZone also runs an individual registration form at r.silverzone.org, described on its own pages as being for individual registrations rather than school ones; we have not been able to confirm which papers it covers or what closing date applies to it, so treat the 30 September date as the school route’s and ask SilverZone directly about the other.

Preparing once for both papers

The registration route and the section weights change between these two exams. The underlying mathematics does not: both are set on the current NCERT Ganita Prakash book for your child’s class, asked in an olympiad shape. A child who is genuinely fluent in this year’s chapters and has met enough olympiad-pattern questions to recognise the shapes is prepared for either paper, and the honest extra work for the second exam is section practice rather than new syllabus.

That second half is what a workbook struggles with, because a book cannot generate a question it does not already contain. OlympAI generates olympiad-pattern practice for Classes 6 to 8 across all five subjects — up to 200 practice questions a day, per subject — and the first subject is free, with full paid features, through 31 March.