CST, TS or SN: what each Sec 4 math sequence keeps open

The three sequences, in plain words

Secondary 3 math is the same for everyone. At the end of that year students choose one of three options (in French, séquences) for Secondary 4 and 5:

• CST: Cultural, Social and Technical (Culture, société et technique).
• TS: Technical and Scientific (Technico-sciences).
• SN: the Science option (Sciences naturelles; the ministry's English documents call it simply “Science”).

The Quebec Education Program asks that the choice be “as consistent as possible with their aspirations, interests and aptitudes.” All three count toward the high school diploma (DES), whose rules require Secondary 4 math in any sequence.

What each one teaches, and who it is for

CST

Designed for students “who like to design objects and activities, develop projects or participate in making them”. It uses more statistics and discrete mathematics, and the program says it prepares students for the arts, communications, the humanities and the social sciences.

• Secondary 4: linear, quadratic, exponential, step and periodic functions read from graphs and tables; systems of equations; percentiles and correlation; lines on a grid; triangles with the sine law and Hero's formula.
• Secondary 5: optimization with linear programming, interest and financial mathematics, logarithms, probability and fair games, networks and paths (graph theory), and comparing voting procedures.

TS

Designed for students “who wish to explore situations that sometimes involve both manual and intellectual work”: case studies, finding the error in a process, the mathematics inside technical instruments. The program names technical fields related to nutrition, biology, physics, business administration, the fine arts and graphic arts.

• Secondary 4: radicals and powers, quadratic functions, exponential and greatest-integer functions, conditional probability and expectation, standard deviation, lines, and trigonometry in right triangles.
• Secondary 5: quadratic, rational and trigonometric functions and their inverses, operations on functions, conics, the unit circle and trigonometric identities, vectors, and the sine and cosine laws.

SN

Designed for students “who seek to understand the origin of different phenomena and how they work”. Students write formal proofs and do “more complex algebraic operations”, and the program says it prepares them for the hard sciences.

• Secondary 4: algebraic identities and factoring, second-degree equations and inequalities, the quadratic function in all three of its forms, systems mixing a line and a parabola, and the sine and cosine laws.
• Secondary 5: absolute value, square root, rational, exponential, logarithmic and trigonometric functions, operations on functions, the unit circle and identities, vectors, and conics.

Which CEGEP programs ask for which

On top of the high school diploma, the ministry sets special conditions program by program. From its admission conditions, January 2026 edition:

Pre-university programs (two years)

• TS or SN Secondary 5, plus Secondary 5 chemistry and physics: Science (200.B1); Science, Computer Science and Mathematics (200.C1); Arts and Sciences (700.A1).
• Secondary 4 math, any sequence: Social Science (300.A1). A student who takes its optional differential calculus, integral calculus or linear algebra, which the program lists as prerequisites for certain university programs, needs TS or SN Secondary 5.
• No math condition beyond the diploma: Arts, Literature and Communication (500.A1), Music (501.A0), Dance (506.A0), Visual Arts (510.A0).

Technical programs (three years)

Some examples:

• No math condition: nursing (Soins infirmiers, 180.A0, which asks for science instead), early childhood education (Techniques d'éducation à l'enfance, 322.A1).
• Secondary 4 math, any sequence: police technology (Techniques policières, 310.A0).
• CST Secondary 5, or TS or SN Secondary 4: computer science technology (Techniques de l'informatique, 420.B0), mechanical engineering technology (Techniques de génie mécanique, 241.A0).
• TS or SN Secondary 4: architectural technology (Technologie de l'architecture, 221.A0), respiratory therapy (Techniques d'inhalothérapie, 141.A0).
• TS or SN Secondary 5: civil engineering technology (Technologie du génie civil, 221.B0), laboratory technology (Techniques de laboratoire, 210.A0).

Several of them also require a science course.

Changing your mind later

• During high school. The program allows a switch at the end of Secondary 4 “only in certain specific cases,” and a move from CST to SN “may require a compensatory measure, to be determined by the school.” A student who switches is expected to “devote all the time they need” to the new material.
• After high school. A missing math condition can be made up with upgrading courses defined by the ministry: one for Secondary 5 TS (90 periods), written for students who already have Secondary 4 TS or SN, and one for Secondary 4 TS (75 periods), written for students coming from CST. Colleges are not obliged to offer them; where one does not, the student takes the course at the secondary level, usually in adult education. None of it counts toward the CEGEP diploma, so the door reopens, at a cost in time.

How to help your teen choose

1. Ask which CEGEP programs they are even curious about, and find each one's row in the ministry's list. If its only math condition is TS or SN, CST closes it, short of the upgrading above.
2. Look at their Secondary 3 algebra specifically, not just the overall mark, and ask the math teacher which option they recommend and why.
3. If it is TS against SN, admission treats them alike, so choose on how your teen learns: applied case studies, or proof and abstraction.

When outside help makes sense

When your teen is set on a path that needs TS or SN and their Secondary 3 algebra is already shaky, plan support for the first term rather than waiting for the report card. The same goes for a switch between options. In my sessions that means a short written diagnostic first; practice between sessions, if your teen wants it, written for the exact topic and marked before the next one; and a written recap after every session to whoever booked. Sessions run in person in Montreal or on Zoom.

To see the SN level before choosing, try one of the free Secondary 4 worksheets, written to the SN program. Already worried about this year? Read seven signs your teen is falling behind in Sec 4 math.

See the Secondary 4 and 5 level

• Secondary 4 math worksheets (SN)
• Secondary 5 math worksheets (SN)