Marking scripts year after year, certain mistakes show up so often they’ve become predictable. What’s interesting is how rarely these are actual knowledge gaps. Most are habits — small, fixable patterns that quietly eat marks from students who genuinely understand the underlying maths. Here’s what shows up most, and what actually fixes each one.

Misreading the Question, Not Misunderstanding the Maths

This is the single most common cause of lost marks, and it’s almost invisible from a distance because the working is often flawless. A child solves for the wrong quantity — finds the total when the question asked for the difference, or finds one person’s share when it asked for two people’s combined share. The maths itself is correct. It’s just answering a question that wasn’t actually asked.

The fix isn’t more practice questions. It’s a specific habit: underline exactly what the question is asking for before starting any working, and check that underlined phrase again once an answer is reached. Sounds too simple to matter, but the marks recovered by this one habit alone are genuinely significant.

Skipping Units, or Mixing Them Up Mid-Question

Converting between centimetres and metres, or millilitres and litres, trips up more students than it should given how simple the conversion actually is. The mistake usually isn’t not knowing that 1m equals 100cm — it’s forgetting to convert at all partway through a multi-step problem, so the final answer is off by a factor of ten or a hundred. This tends to happen when a question mixes units within the same problem, because attention is on the harder logical step and the conversion gets treated as an afterthought.

A simple habit fixes most of this: writing the unit next to every number in the working, not just the final answer. Without a clear label, it’s easy to lose track of which unit applies where, several steps later.

Forgetting to Answer in the Form the Question Actually Wants

Some questions ask for an answer as a fraction. Others want a percentage, a specific unit, or a rounded decimal. A student can do every step correctly and still lose the final mark because the answer wasn’t presented in the format the question specified. It’s a frustrating one for parents to watch, because it looks like carelessness rather than a real gap — and in a sense it is, but a fixable kind.

The fix is the same underline-and-recheck habit as the misreading problem above, just applied to the final line of the question instead of the opening one. Reading the last sentence twice, right before writing the answer, catches most of these.

Rushing the Easy Questions and Running Out of Time for the Hard Ones

This one’s about pacing, not knowledge, and it shows up constantly in students who are otherwise strong. Booklet A questions get rushed because they feel trivial, sometimes so rushed that a careless error creeps in on what should’ve been an easy mark. Then time runs short for the demanding Booklet B word problems, where a panicked attempt produces a worse result than a calm one would have.

The counterintuitive fix is slowing down slightly on the easy questions, not speeding up on the hard ones. A student who takes an extra ten seconds per easy question to actually read it properly rarely loses meaningful time overall, and the reduction in careless errors on those questions usually outweighs the small time cost many times over.

Not Showing Working, Then Losing Method Marks on a Wrong Final Answer

Some students, particularly ones strong at mental arithmetic, skip showing working because they don’t need it to get the right answer most of the time. The problem is what happens on the rare occasion they make an arithmetic slip — with no working shown, there’s nothing for a marker to award partial credit against, and a single small error costs the entire question’s marks instead of just one or two.

This habit is genuinely hard to break because it’s tied to actual confidence and ability, which makes it feel unnecessary to the student. The way around it is reframing working as a safety net rather than busywork — something that protects marks on a bad day rather than proof of ability on a good one.

Why These Habits Matter Beyond Math Test Itself?

Here’s the part that doesn’t get said enough: these habits don’t disappear after Primary 6. A student who’s careless about units or rushes through easy questions carries that same pattern straight into secondary school, where the maths gets harder, and the room for careless error gets smaller, not larger. 

This is exactly why families who start looking into secondary Math tuition early in Secondary 1 or 2 often find they’re not actually fixing new content gaps — they’re fixing the same habits that were quietly present back in Primary 6 and never fully addressed.

A good secondary Math tutor will often say the same thing: content difficulty aside, the students who struggle most in Secondary 3 and 4 are frequently the ones whose careless habits from primary school were never corrected, not the ones who genuinely lack ability. Fixing these patterns early, while the stakes are lower, saves a lot of frustration several years down the road.

Getting Ahead of It Rather Than Reacting to It

Families searching for secondary Math tuition Singapore parents actually recommend tend to be at their most effective when they start that search proactively, right around the transition into secondary school, rather than waiting for a poor Secondary 2 report card to force the issue.

The same logic applies to finding a secondary Math tutor Singapore families trust for the long haul — someone who catches habit-based errors early saves a student far more marks over several years than someone brought in only after a crisis has developed.

The Bottom Line

Almost none of these mistakes are about a child lacking mathematical ability. They’re about habits formed early and left unchecked, and habits respond well to deliberate, specific correction rather than generic extra practice. 

Catching them in Primary 6, or even earlier, tends to matter far more than the exam itself — because these are exactly the same habits that will decide how comfortably a child handles secondary school Maths a few years later.