HK Maths Competitions for Primary Students: HKMO, IMAS, and How to Prepare

If you've decided your child is ready to try maths competitions (and you've read my article on whether olympiad maths is worth it for average students), the next question is: how do you actually prepare?

This article is the practical follow-up: what each major competition tests, how to get past papers, and what a realistic preparation timeline looks like.

The Main Competitions: An Overview

HKMO (Hong Kong Mathematical Olympiad) — Primary Section

What it is: The most prestigious primary maths competition in Hong Kong, organised by the Hong Kong Mathematics Olympiad Association.

Format:

• Heat Event: 30 multiple-choice questions, 1 hour. Open to P5 and P6 students. Held in October/November.
• Individual Short Problem Event: 5 short-answer problems, increasingly difficult. Selective entry based on Heat Event performance.
• Group Event: Team competition for schools.

Difficulty level: The Heat Event is accessible to well-prepared P5–P6 students. The Short Problem Event is very challenging — expect to find it hard even with preparation.

What it tests: Number theory basics (factors, multiples, primes), combinatorics (counting arrangements), geometry (areas, angles, properties of shapes), algebra (patterns, equations), and logical reasoning.

Past papers: Available from the HKMO official website and most HK educational bookshops ($20–$40 per year).

IMAS (International Mathematics Assessment for Schools)

What it is: A Taiwan-based competition with wide participation from HK schools. More accessible entry point than HKMO.

Format:

• First Round: 25 questions (multiple-choice and short answer), 75 minutes. Held in November.
• Second Round: Harder version for students who perform well in Round 1. Held in February.

Difficulty level: First Round is well-suited to motivated P4–P6 students. Second Round approaches HKMO Heat difficulty.

What it tests: Similar topics to HKMO but with slightly more emphasis on straightforward application and slightly less on pure competition tricks.

Past papers: IMAS publishes official past papers. Many Hong Kong bookshops stock them; they're also available online from the IMAS official website.

AMC 8 (American Mathematics Competition)

What it is: A US-based competition increasingly popular with international and DSS schools in Hong Kong.

Format: 25 multiple-choice questions, 40 minutes. Open to students in Grade 8 (S2) equivalent and below.

Difficulty level: Broadly comparable to IMAS First Round for most topics, with some questions requiring more creative thinking.

Why HK students sit it: Some DSS and Band 1 schools include AMC results in their co-curricular activity profiles. International students applying to US schools may benefit from the brand recognition.

Preparation Strategy by Competition Type

12-Week Preparation Plan for HKMO Heat Event

Weeks 1–3: Topic audit Work through one past Heat paper without time pressure. Categorise every question you can't solve by topic:

• Number theory (factors, multiples, LCM, HCF)
• Combinatorics (counting, permutations)
• Geometry (area, perimeter, angle properties)
• Algebra/patterns
• Word problems (rate, mixture, work-rate)

Identify your weakest 2–3 topic areas.

Weeks 4–7: Topic-by-topic enrichment For each weak topic:

• Work through the relevant section of a competition maths book (see recommendations below)
• Do 10–15 exercises from past papers on that topic only
• Aim to understand each solution approach, not just get answers

Recommended books available in HK bookshops:

• Primary Maths Olympiad Training series (奧數訓練) — widely stocked, covers all major topics
• Competition Mathematics for Elementary School (華羅庚金盃) — harder, for advanced preparation

Weeks 8–10: Mixed practice Do full past papers under timed conditions. For a 30-question, 60-minute Heat Event, that's 2 minutes per question. Practise strict timing.

After each paper:

• Record your score and which questions you missed
• For each missed question: categorise as "didn't know the method" or "knew the method but made an error"
• Spend 15 minutes per paper reviewing the "didn't know" questions

Weeks 11–12: Consolidation Reduce volume, maintain confidence. 2–3 papers in the final two weeks. Focus on mental fluency and quick recognition of question types.

For IMAS (Less Intensive Preparation)

IMAS First Round can be approached with 4–6 weeks of preparation:

• Complete 2–3 past IMAS papers to understand the format
• Focus on clean, systematic problem-solving rather than competition tricks
• Time yourself: 3 minutes per question for the 25-question paper

Specific Topics to Target

These topics appear in virtually every HK primary competition and are worth mastering specifically:

1. LCM and HCF problems Competition questions use LCM and HCF in non-routine ways. E.g., "Bells A and B ring every 6 and 8 minutes respectively. They ring together at 9am. When do they next ring together?" (Answer: LCM of 6 and 8 = 24 minutes later, at 9:24am.)

2. Counting problems "How many two-digit numbers have a digit sum of 9?" (18, 27, 36, 45, 54, 63, 72, 81, 90 = 9 numbers.) Systematic counting without repeating or missing is a trainable skill.

3. Area of irregular shapes Finding the area of L-shapes, overlapping rectangles, shapes with pieces cut out. Always decompose into rectangles.

4. Rate and work problems "3 workers take 12 days to complete a job. How long do 4 workers take?" (3 × 12 = 36 work-days; 4 workers: 36 ÷ 4 = 9 days.)

Managing Expectations

In any given year, the top 10% of HKMO Heat participants receive a bronze award or higher. Preparing thoroughly and performing at your ability level is success, regardless of the award outcome. Many students find that competition participation is most valuable not for the result but for the problem-solving habits it builds.

Compete because you love the challenge. Prepare well because effort is worth respecting. Let the result take care of itself.