Primary 4 covers multiplying and dividing decimals up to 2 decimal places by a 1-digit whole number, dividing a whole number by a whole number with a decimal quotient, and rounding answers to a specified accuracy.
What multiplying and dividing decimals actually asks of a Primary 4 student
Dividing a whole number by a whole number and getting a decimal is the significant new idea. Until now such a division either came out exactly or produced a remainder; now it can continue past the point.
That means the concept of a remainder is replaced, not extended, and children who have firmly learned remainders can find this unsettling.
Rounding to a specified degree of accuracy also arrives, so the question now dictates how the answer should be presented.
What the syllabus covers
Under the MOE primary mathematics syllabus, multiplying and dividing decimals at Primary 4 covers:
- multiplying and dividing decimals (up to 2 decimal places) by a 1-digit whole number
- dividing a whole number by a whole number with quotient as a decimal
- rounding answers to a specified degree of accuracy
Where the marks actually go
The decimal point misplaced in the answer, most often in division.
Division stopped at the remainder instead of continuing into decimal places.
Answers not rounded as instructed, or rounded to the wrong accuracy.
How to practise this properly
Estimate before dividing. If 7 ÷ 4 is a bit less than 2, an answer of 17.5 is obviously wrong.
When dividing a whole number, write it with a decimal point and zeros — 7 as 7.00 — so continuing past the point feels natural.
Underline the rounding instruction in the question before starting, so the final step is not forgotten.
Check multiplication answers by estimating: 3.2 × 4 should be a little over 12.
What this leads to
Primary 5 multiplies and divides decimals by 10, 100 and 1000 and converts measurements in decimal form. Both depend on the point being placed confidently.
Almost every primary topic is scaffolding for a later one, and the scaffolding is invisible until it gives way. That is why our curriculum is written across all six years, Primary 1 to Primary 6, rather than level by level — it lets us see the whole structure a child is standing on, not just the step they are currently on.
What lessons at Odyssey are actually like
A student on how the lessons work in practice. The clip is from our secondary classes, but the way concepts are explained is the same at every level. More are on Odyssey Math TV.
Getting help with this topic
We teach Primary 4 maths in small classes at Hexacube, 160 Changi Road #01-02, about three minutes from Eunos MRT. You can see our class schedules and fees, read about our math tutors, or look through the primary school math tuition programme as a whole. If your child is in a nearby school, our primary school directory may be useful too.
If you are unsure whether tuition is the right answer yet, the free trial is a reasonable way to find out without committing to anything. We will give you an honest read on where your child stands and what would actually help. Book a free trial class or WhatsApp +65 8512 6882.
What we describe here comes from teaching this syllabus in our own classes since 2012. It is not a forecast for any individual child: progress is produced jointly, by a student willing to do the work with support at home. We do not promise grades. Topics follow the MOE primary mathematics syllabus — check the current syllabus on the MOE website for the definitive version, and see our curriculum page for how we teach it.
Frequently asked questions
What can decimals be multiplied by at Primary 4?
A 1-digit whole number, with the decimal up to 2 decimal places.
What happened to remainders?
When a quotient is asked for as a decimal, the division continues past the point instead of stopping at a remainder. Both ideas are valid; the question decides which is wanted.
How do I know how much to round?
The question specifies it. Underlining that instruction before starting prevents the commonest lost mark in this topic.
Is a calculator used?
Not at Primary 4 for this topic. The written methods are what is assessed.
