CST, TS or SN: choosing your Secondary 4 and 5 math sequence

Three sequences, three ways of doing math

At the end of Secondary 3, students choose the math sequence they will follow in Secondary 4 and 5. Quebec's Ministry of Education offers three: Cultural, Social and Technical (CST), Technical and Scientific (TS) and Science (SN). Think of them as different kinds of math for different purposes, not as "weak, average and strong" groups.

The Fédération des cégeps notes that TS and SN build the same competencies and cover essentially the same content, using different approaches. The official breakdown is in the Ministry's Progression of Learning in mathematics (French).

Who each sequence suits

CST: students heading toward the arts, communications or social sciences

CST works well for students who like math when it connects to real life (budgets, elections, planning) and whose plans do not run through the pure sciences. It is a solid choice, not a fallback.

TS: hands-on students who like to know how things work

TS suits students who learn best by measuring, building and modelling real problems. It prepares students especially well for technical cégep programs (computer science, engineering technology, biology, administration) while opening the same pre-university doors as SN.

SN: students drawn to abstraction and pure science

SN fits students who enjoy reasoning, proving and working with algebra for its own sake. It is designed mainly as preparation for the Science program at cégep and for university science.

Many schools set a minimum Secondary 3 math mark for TS or SN, often around 75%. The cut-off varies by school, so check your school's course selection guide.

Cégep prerequisites: what is actually required

The Secondary School Diploma (DES) requires Secondary 4 math in any sequence. Beyond that, some cégep programs set specific prerequisites. A few verified examples:

• Science (200.B1): Secondary 5 TS or SN math, plus Secondary 5 chemistry and Secondary 5 physics (Dawson College).
• Social Science without math: Secondary 4 CST is enough. For the profile with math, Cégep de Saint-Laurent requires Secondary 5 TS or SN.
• Computer Science Technology: at Cégep de Sainte-Foy, Secondary 4 TS or SN, or Secondary 5 CST.

Two takeaways. First, CST 5 does not open the door to the Science program. Second, TS 5 counts just as much as SN 5 for Science. Requirements can differ by program and by college, so always confirm on the official page of the program your child is aiming for. Vocational training (DEP) remains open to students from every sequence.

Switching sequences: possible, but plan for it

In principle, students can change sequences between Secondary 4 and Secondary 5. In practice, it depends on the direction:

• Moving from SN or TS down to CST is usually straightforward, since the Secondary 4 content more than covers it.
• Moving from CST up to TS or SN requires extra learning. Some schools offer bridges (catch-up sessions, summer courses), others do not.
• Moving between TS and SN is more common, because the content overlaps heavily.

Missing a prerequisite at the end of high school is not a dead end. Several cégeps run a Tremplin DEC (springboard) path with upgrading courses, and adult education centres also offer missing courses. Keep in mind that these options often require Secondary 4 TS or SN already, and they can add a semester or more to the timeline.

How to decide: a five-step approach

1. Start from interests, even vague ones. Ask your teen to name two or three fields that appeal to them. If any leads to Science at cégep or to a math-heavy technical program, TS or SN should come first.
2. Check real prerequisites on cégep websites instead of relying on what classmates say.
3. Look at marks and at learning style. A student comfortable with abstraction may thrive in SN; one who understands through concrete examples often does better in TS.
4. Talk to the math teacher and the guidance counsellor. They know your child and the school's rules.
5. Consider the total workload. TS and SN carry 6 credits a year instead of 4, and are often paired with the STE science option, then chemistry and physics in Secondary 5. Your teen still needs time for everything else.

Warning signs worth taking seriously

• Picking SN "to keep every door open" when math is already a struggle. A failing or weak SN mark can close more doors than a strong TS or CST mark.
• A Secondary 3 mark barely at the cut-off, reached with a lot of last-minute help. TS and SN move faster.
• A choice driven by friends or family pressure rather than by the student's own interests.
• A sharp drop in the first term of Secondary 4. Act early: talk with the teacher, adjust study habits, consider support, and only then revisit the sequence.
• Forgetting what comes next. High school marks drive cégep admission, and the R score then matters for university. Our R score calculator shows how it works.

Supporting the decision

The right sequence keeps the doors your child cares about open and is one they can pass with reasonable effort. Talk it through as a family, using facts rather than each sequence's reputation.

If your teen is torn between two sequences or wants to firm up the basics before Secondary 4, Stellaire Académie offers math tutoring for CST, TS and SN. You can book a first session to take stock together.

Frequently asked questions