Which paper tests what: decimals appears 40 times, and never in Paper 2

A while ago, we set ourselves a slow, unglamorous job. We tagged 709 PSLE math questions across fourteen years, recording for each one the topic it tested, how hard it was, and which paper it appeared in. That last column, the paper a question lived in, turned out to be the most useful one of all, and it is the one almost no one looks at.

Here is the figure that made me stop and read it twice. Decimals appeared 40 times across those fourteen years, and not once in Paper 2. Not a single time. Every appearance was in Paper 1, almost always as a quick, single-step item: convert this, round that, place the point. It was never the engine of a multi-step puzzle.

A quick word on how we counted

To keep this honest, the numbers above are drawn from the 664 questions in the fourteen actual papers sat between 2012 and 2025. The MOE Specimen paper adds another 45 questions, and we report those separately so a practice paper does not get blended in with the real exams. So when I say "40 times" and "fourteen years", that is the sat-paper record, counted by hand, not an estimate.

Decimals is not alone in this

Once we noticed the pattern with decimals, we went looking for it elsewhere, and it kept turning up. The same "Paper 1 only" behaviour holds, across all fourteen years, for a clear group of topics:

• +Symmetry. Tested, but as recognition: which figure has a line of symmetry, where does it fall. It never anchors a long Paper 2 problem.
• +Nets. A spatial check, fold-this-into-that. Quick to do, quick to mark, firmly in Paper 1.
• +Tessellation. The same story: a short, visual item, never the spine of a multi-step question.
• +Data tables. Reading a value off a table is a single-step task, and it has stayed one.

None of these are unimportant. They carry real marks, and a child who fumbles them is leaving easy marks on the table. The point is narrower than that, and more useful: these are speed-and-accuracy topics, not puzzle topics.

Why this changes where your child practises

This is the part that matters at your kitchen table. Knowing which paper tests a topic is not trivia, and it is not for impressing anyone. It changes where a child spends their practice time.

If decimals only ever appears as a one-step Paper 1 item, then drilling decimals as if it were a Paper 2 puzzle, hunting for the deep trick, the hidden structure, is effort spent in the wrong place. What that topic actually rewards is being fast and accurate, every time, without a slip. The right practice for it looks like short, clean repetition under a gentle clock, not long, agonised problem sets.

Flip it around and the same logic frees up your child's harder hours. The topics that genuinely reward slow, structured thinking are a different set, and they deserve the bulk of the deep practice. When practice time is matched to what a topic actually demands, the same number of hours simply does more. If you want to see which topics carry the heaviest weight, and where the real multi-step puzzles cluster, we lay it all out in our pillar guide to the most tested PSLE math topics.

One honest caveat

This is an analysis of past papers, not a prediction of the next one. MOE can and does vary how it sets the exam, and nothing here should be read as a forecast of where a topic will land in your child's year. What fourteen years of tagged questions can tell you is the shape of the recent past, clearly enough to plan practice around. That is what we use it for, and it is all I would ask you to use it for too.