O-Level to SEC in 2027: what changes for maths and science

From 2027, the GCE O-Level, N(A)-Level and N(T)-Level examinations are combined into one: the Singapore-Cambridge Secondary Education Certificate (SEC). Students who started Secondary 1 in 2024, the first cohort under Full Subject-Based Banding, sit it in 2027. The 2026 papers are the last O-Levels. SEAB says the standard of the examinations does not change. What changes is the name of each level, the syllabus codes, the exam calendar and, from 2028, how the score for junior college admission is counted.

Who sits which exam

Sec 4 in 2026

GCE O-Level, October to November 2026. Results in January 2027: see O-Level results 2026.

Sec 3 in 2026

SEC, in 2027. Results in January 2028, used for the 2028 post-secondary admissions.

G1, G2 and G3

Under the SEC, each subject is taken at a level: G1, G2 or G3, with G standing for General. The levels map from the old N(T), N(A) and Express standards. G3 is the O-Level standard, and a student can take different subjects at different levels. Everyone receives one certificate that lists each subject with the level it was taken at.

Grades stay the same

G3 subjects keep the O-Level grades: A1, A2, B3, B4, C5, C6, D7, E8 and 9. The assessment format also stays the same, so a student preparing for G3 Additional Mathematics is preparing for the same kind of paper as O-Level Additional Mathematics. A certificate is awarded for a G3 subject at E8 or better.

New syllabus codes

Every subject has a new code for 2027. These are the G3 codes for the mathematics and science subjects, from SEAB’s list for school candidates.

When buying practice papers, check which code a paper was written for. Past O-Level papers remain good practice for G3, because the standard and format are unchanged.

A new exam calendar

English Language and Mother Tongue written papers move to September. All other written papers, including mathematics and the sciences, are held in one common period starting in October. Science practicals, orals and listening comprehension stay before the written papers. Results come out in January, as O-Level results do now.

Junior college admission: L1R4 from 2028

This is the change that matters most for students aiming for junior college. From the 2028 admissions exercise, JC admission uses an L1R4 score instead of L1R5: one first language and four relevant subjects, all taken at G3. Work one out with the L1R4 calculator.

JC

L1R4 of 16 or less. Millennia Institute: 20 or less.

L1

G3 English, or Higher Mother Tongue.

R1

Best G3 humanities subject.

R2

Best G3 mathematics or science subject.

R3

Best G3 humanities, mathematics or science subject.

R4

Best of any other G3 subject.

Also needed

G3 English at A1 to C6, and G3 Mathematics or G3 Additional Mathematics at A1 to D7, plus the Mother Tongue requirement.

Bonus points are capped at 3, as now. An O-Level result counts as the G3 equivalent.

With one fewer subject counted, each grade weighs more. One grade band in A Math or Physics is a larger share of an L1R4 score than it was of an L1R5 score.

What to do in Sec 3

1. Check each subject’s level. Only G3 subjects count toward L1R4 for junior college.
2. Keep using past O-Level papers. The standard and format are the same, so they are still the best practice material for G3.
3. Plan around the new calendar. With English in September, mathematics and science papers now come in one block from October.
4. Learn how the marks are given. Most marks in a maths paper are for the steps, not the final answer. See how method marks work.

Sources

SEAB, Secondary Education Certificate (SEC) and 2027 G3 syllabuses for school candidates. MOE, JC and MI admission criteria from the 2028 PSE. Details can change, so check these pages before making a decision.

How we teach for it

Our Sec 3 and Sec 4 classes follow the G3 syllabuses, in classes of five, with every piece of work marked against the scheme. See Additional Mathematics and Mathematics (E Math), or book a trial class.