📐 Class-wise preparation · 6 min read
Class 4 IMO preparation: the year fractions and geometry arrive
How to prepare a Class 4 child for the SOF IMO: large numbers, roman numerals, fractions and geometry — plus a routine that fits a nine-year-old.
Class 4 is where the IMO stops being “Class 3 with bigger numbers”. Two genuinely new strands enter the syllabus — fractions and geometry — and both reward understanding over memorisation. A child who can picture what a fraction means, and what perimeter measures, finds Class 4 olympiad questions surprisingly friendly. A child who only memorised rules finds them slippery.
As always, the paper stays anchored to the school curriculum; the olympiad twist is in how questions are phrased. Preparation is a matter of making each topic genuinely comfortable, then practising the exam’s multiple-choice, lightly-tricky style.
What the Class 4 syllabus covers
| Topic | Key subtopics |
|---|---|
| Number Sense | large numbers up to 5–6 digits, place value, comparing and ordering, roman numerals |
| The four operations | multi-digit addition, subtraction, multiplication and division; word problems |
| Fractions | fractions of a whole and of a collection, equivalent fractions, comparing fractions |
| Geometry | basic shapes and their properties, perimeter of squares and rectangles |
| Money, Time & Measurement | unit conversion, calendar and clock problems, everyday calculations |
| Patterns & Logical Reasoning | series, coding patterns, direction sense, ranking |
Where Class 4 children typically wobble
- Roman numerals: children learn the symbols but stumble on subtraction pairs like IX and XL. Little and often fixes this.
- Comparing fractions: “1/8 is bigger than 1/4 because 8 is bigger than 4” is the classic error. Draw it — a pizza cut into 8 gives smaller slices.
- Equivalent fractions: multiplying top and bottom by the same number needs to feel like “same amount, different cutting”, not a trick.
- Perimeter vs area language: even before area is formally introduced, questions probe whether a child knows perimeter is the distance around.
- Large numbers: reading 5-digit numbers aloud, with correct place names, is the quiet foundation for every comparing-numbers question.
A sensible weekly rhythm
Three or four sessions of 15–20 minutes a week is plenty. Spend most weeks on a single topic until it feels easy, and keep one short session for mixed revision so earlier topics stay warm. Introduce full timed mocks only in the final month — by then the math is in place and the mock is teaching pace and composure, not content.
✏️ A Class 4 flavour question
A rectangular garden is 8 m long and 5 m wide. Riya walks exactly once around its boundary. How far does she walk?
- A13 m
- B40 m
- C26 m
- D21 m
Show the answerAnswer: 26 m
Answer: 26 m. The distance around a rectangle is its perimeter: 8 + 5 + 8 + 5 = 26 m. The wrong options are the classic traps — 13 is just length + width, and 40 is length × width. An olympiad question rarely invents new math; it checks whether the child knows which calculation the situation is asking for.
What good looks like by exam time
A well-prepared Class 4 child can explain why two fractions are equivalent using a picture, can find the perimeter of any rectangle without a formula card, and reads every question to the end before choosing an option. That last habit alone recovers more marks than any extra topic drilling.
LittleMathematicians covers each of these Class 4 topics as its own adaptive level — the mastery score picks questions right at the edge of your child’s ability, so fractions practice never gets boring or brutal — and timed mocks in the official pattern round out the final weeks. It is free during early access.
Practice this the fun way
Adaptive levels, exam-pattern mocks and progress you can see — free during early access.
Start free