Primary 6 covers finding the whole given a part and the percentage, and finding percentage increase and decrease.
What percentage actually asks of a Primary 6 student
The questions reverse. At Primary 5 the whole was given; now a part and its percentage are given and the whole must be found.
That reversal is what makes this topic hard. Working backwards requires dividing by the percentage rather than multiplying, and children apply the familiar forward method by habit.
Percentage change adds a second trap: the increase is always measured against the original value, not the new one.
What the syllabus covers
Under the MOE primary mathematics syllabus, percentage at Primary 6 covers:
- finding the whole given a part and the percentage
- finding percentage increase/decrease
Where the marks actually go
Calculating percentage change against the new value instead of the original.
Multiplying when working backwards, so the answer is smaller than the part it came from.
In multi-step problems, applying the second percentage to the original figure when it should apply to the new one.
How to practise this properly
Identify what counts as 100% before doing anything. Almost every error in this topic is an error about which quantity that is.
Sanity-check backwards questions: the whole must be larger than the part.
For percentage change, write the original underneath as the denominator before calculating. Making it explicit prevents the substitution.
Work through both directions in the same session, since forward and backward questions fail differently.
Work a rise and a fall of the same percentage on the same starting figure and compare the result with the original. Discovering that it does not return to the start is the clearest demonstration that percentage change always refers to whichever value came before it.
What this leads to
Secondary work on reverse percentages, compound interest and proportional change is a direct extension of exactly this reasoning.
It is also why a difficulty in one year is so often a leftover from an earlier one. Because our curriculum spans Primary 1 through Primary 6, we can go back to the genuine cause rather than treating the symptom in front of us. A child struggling with Primary 5 fractions frequently has a Primary 3 equivalence problem, and no amount of Primary 5 practice will resolve it.
What lessons at Odyssey are actually like
What the teaching looks like from a student’s side. This is a secondary student — primary lessons follow the same approach at an age-appropriate pace. More are on Odyssey Math TV.
Getting help with this topic
We teach Primary 6 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.
Start with the free trial lesson. We use it to work out where the difficulty really sits, and we will say so plainly — including if we think the sensible course is to wait a term and watch. Parents generally find that more useful than a confident sales answer. Get in touch 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
How do you find the whole from a part?
Divide the part by the percentage and multiply by 100. If 20% is 15, then 1% is 0.75 and 100% is 75.
Is percentage change measured against the old or new value?
Against the original value, always. This is the commonest error in the topic.
Why is my answer smaller than the part I started with?
Because you multiplied when you needed to divide. The whole is always larger than a part of it.
Does a 20% rise then a 20% fall return to the start?
No, because the fall is calculated on a larger figure. Working an example through is the clearest way to show it.
