The 2027 SEC for Maths and Science: Every Subject Code and Paper, Confirmed

Short answer. From 2027 the O-Level is replaced by the Singapore-Cambridge Secondary Education Certificate, and every maths and science subject gets a new code. At G3 the codes are K310 Mathematics, K341 Additional Mathematics, K323 Physics, K324 Chemistry, K325 Biology, and K326, K327 and K328 for the three Combined Science pairings. At G2 they are K210 Mathematics, K232 Additional Mathematics, and K223, K224 and K225 for Combined Science. The paper structures, durations, marks and weightings are the same as the O-Level papers your child’s school has been preparing for. If your child is in Sec 3 or below in 2026, this is the certificate they will sit.

The short version of the whole change: the certificate is new, the codes are new, the banding is formalised, and the examinations themselves are close to unchanged. That last point is the one most worth passing on to an anxious fourteen-year-old.

Which cohort sits which examination

Only the 2026 Sec 4 cohort sits the O-Level. Every year group below them sits the SEC.

The reason is Full Subject-Based Banding. The 2024 Secondary 1 cohort was the first to run all the way through under Full SBB, and they reach Secondary 4 in 2027, which is when the new certificate is first awarded. Our explainer on the 2027 SEC and Full Subject-Based Banding covers the wider change, including what happens to streams and to the certificate itself.

The maths codes

Mathematics is the subject everyone takes. Additional Mathematics is taken alongside it, never instead of it, and typically starts in Sec 3.

K310 Mathematics, G3. Two papers, each 2 hours 15 minutes and worth 90 marks, weighted 50% each. Paper 1 is about 26 short-answer questions. Paper 2 is 9 to 10 questions of varying length, and the last question is set specifically on applying mathematics to a real-world scenario. An approved calculator may be used in both papers, so there is no non-calculator paper. The assessment objectives are weighted 45% for using and applying standard techniques, 40% for solving problems in a variety of contexts, and 15% for reasoning and communicating mathematically.

K341 Additional Mathematics, G3. Also two papers of 2 hours 15 minutes and 90 marks, weighted 50% each. Paper 1 runs 12 to 14 questions worth up to 10 marks each. Paper 2 runs 9 to 11 questions worth up to 12 marks each.

Source: SEAB, 2027 SEC G3 syllabuses for school candidates, and the K310 Mathematics syllabus document.

The science codes

Read that table again and notice what is missing. There is no G2 Physics, no G2 Chemistry and no G2 Biology. At G2, science exists only as the three combined pairings. The pure sciences are offered at G3 only.

That single fact decides more than any other line on this page. If your child is banded at G2 for science, the Sec 2 subject decision is not Pure or Combined. It is which of the three pairings, and the route to a pure science runs through moving up to G3 first. Most parents discover this during the subject options exercise in Term 4 of Sec 2, which is late to be finding out.

Source: SEAB, 2027 SEC G2 syllabuses for school candidates.

The science papers, unchanged

Each pure science, G3. Three papers. Paper 1 is multiple choice, 1 hour, 40 marks, 30% of the grade. Paper 2 is structured and free response, 1 hour 45 minutes, 80 marks, 50%. Paper 3 is the practical examination, 1 hour 50 minutes, 40 marks, 20%. The same shape applies to K323 Physics, K324 Chemistry and K325 Biology.

Combined Science, G3. Five papers exist and a candidate sits four of them: Paper 1, Paper 5, and two of Papers 2, 3 and 4. Paper 1 is multiple choice, 1 hour, 40 marks, 20%. Papers 2, 3 and 4 are the structured and free-response papers for Physics, Chemistry and Biology respectively, each 1 hour 15 minutes, 65 marks, 32.5%. Paper 5 is the practical test, 1 hour 30 minutes, 30 marks, 15%.

A student taking K328, Science (Chemistry, Biology), therefore sits Papers 1, 3, 4 and 5. Their multiple-choice paper and their practical test both cover Chemistry and Biology only.

Two things follow from those numbers, and both are worth acting on. The practical is 20% of a pure science and 15% of Combined Science, which is a fifth or a seventh of the grade decided by laboratory work that cannot be revised from notes. And in Combined Science the two structured papers carry 65% of the grade between them, so a student who is strong in one of their two sciences and weak in the other cannot hide it.

What is actually changing, and what is not

Our reading, and this is judgement rather than a SEAB statement: the anxiety around the SEC is out of proportion to the change in the examinations. What has genuinely changed is the architecture around them, which subjects a student can take at which level, and how the results feed into JC and polytechnic admission. The papers themselves your child’s teachers have been preparing them for all along.

Admission is the part that does move. The JC and polytechnic admission rules for the 2027 and 2028 intakes changed alongside the certificate, and the cohort sitting the first SEC goes through a revised aggregate.

What this means for a Sec 1 or Sec 2 parent right now

Nothing about the SEC requires action in Sec 1. Two things about Full SBB do.

The first is subject level. A child banded at G2 for science in Sec 1 is on a path where the pure sciences are not on the menu at Sec 3, and levels move at set points during Sec 1 and Sec 2. If a pure science matters for where your child is heading, the window to move up is the two years before the choice, not the term of the choice.

The second is that lower secondary is where the level review evidence comes from. What your child is covering now in Sec 1 maths and in lower secondary science is the ground the Sec 2 decision is made on.

Frequently Asked Questions

Will my child sit the O-Level or the SEC?

The O-Level only if they are in Secondary 4 in 2026. Everyone in Sec 3 or below sits the Singapore-Cambridge Secondary Education Certificate, first awarded in 2027, at G1, G2 or G3 subject levels.

What is the SEC code for O-Level E-Maths?

Mathematics, which everyone calls E-Math, becomes K310 at G3 and K210 at G2. Additional Mathematics becomes K341 at G3 and K232 at G2.

What are the 2027 science subject codes?

At G3: K323 Physics, K324 Chemistry, K325 Biology, and K326, K327 and K328 for Science (Physics, Chemistry), Science (Physics, Biology) and Science (Chemistry, Biology). At G2 only the combined pairings exist: K223, K224 and K225 in the same order.

Are the SEC papers different from the O-Level papers?

Not in structure. Maths keeps two papers of 2 hours 15 minutes at 90 marks and 50% each. Each pure science keeps a 1-hour multiple-choice paper at 30%, a 1-hour-45-minute structured paper at 50%, and a practical at 20%. Combined Science keeps its multiple-choice paper at 20%, two structured papers at 32.5% each, and a practical test at 15%.

Can my child take Pure Physics at G2?

No. The pure sciences are offered at G3 only. At G2 science is available as Science (Physics, Chemistry), Science (Physics, Biology) or Science (Chemistry, Biology). A student who wants a pure science needs to be at G3 for science by the time the Sec 3 combination is chosen.

Is the practical examination still part of the grade?

Yes, and it is a large part. It is 20% of each pure science and 15% of Combined Science, and it is examined as its own paper rather than assessed by the school.

Does the SEC change what my child is being taught now?

No. The syllabus content is the same. The certificate, the codes and the subject levels are what changed.

Two questions parents ask us at the point of deciding

My child is Sec 2 and banded G2 for science. What do we actually do?

Find out from the school what moving to G3 for science would require and by when, because that is the decision, not Pure versus Combined. If moving up is realistic, the work is in the next two terms. If it is not, the useful question becomes which of the three pairings fits your child, and our secondary science class starts by working out which of the three disciplines they are actually strongest in.

Should we be doing anything different because of the SEC?

No, and be sceptical of anyone selling you an SEC-specific programme. The papers are the same papers. What deserves attention is subject level and the Sec 2 combination decision, which are Full SBB matters rather than SEC ones. Our secondary maths class and our Combined Science class teach the same syllabuses they always did, under their new codes.

Where the numbers on this page came from

Every code, duration, mark total and weighting above was read directly from the SEAB 2027 syllabus documents for school candidates, not from a secondary summary. Where SEAB has not published something, this page does not guess.

If you want a second opinion on your child’s subject level or their Sec 3 combination, come and sit in on a class in Hougang. Classes are capped at five students and we will give you a straight read, including that no tuition is needed if that is what we find.

Secondary maths tuition at Arche Academy | Secondary science tuition at Arche Academy