Source: QCAA Specialist Mathematics General senior syllabus 2025 v1.4, March 2026. Unit 1 is Combinatorics, proof, vectors and matrices (printed p 15), a notional 55-hour unit (printed p 4). Unit 1 Topic 1, Combinatorics, has two subtopics: Introduction to counting techniques (4 hours) and Permutations (ordered arrangements) and combinations (unordered selections) (8 hours), printed pp 16–17. Ten 25-minute periods = 250 minutes = 4 hours 10 minutes. Our scripts use those 250 minutes as an opening sequence around the first subtopic; the 10-minute difference is timetable structure, not a claim that QCAA changed its allocation.
| Official subject matter, paraphrased | Where the opener teaches it | Evidence and boundary |
|---|---|---|
| Inclusion–exclusion for union of two sets | Days 1–2, 5, 9 | A/B, fresh G; overlap is subtracted once |
| Inclusion–exclusion for union of three sets | Days 3, 8–10 | C, fresh H; pairwise overlaps include the triple, which is added back |
| Multiplication principle | Days 6–7, 9–10 | E/F, fresh I; sequential choices form a product |
| Addition principle | Days 4, 7, 9–10 | D/F, fresh G/I; branches must be mutually exclusive or adjusted for overlap |
| Recall, use, communicate, reasonableness, justification, problem solving (Unit objectives, printed pp 15–16) | All days | Count, represent, check and explain in an accessible mode |
| Permutations/combinations including restrictions and probability | Future 8-hour subtopic, not taught here | No factorial, nPr/nCr or ordered-arrangement claim in this starter |
| Topic 2 proof; later vectors/matrices | Future Unit 1 topics, not taught here | A reason for a count is required, but no claim of formal Topic 2 proof coverage |
There are no invented official lesson codes. The two public formative checks and their worked key are not secure school instruments or a QCAA unit judgment. The syllabus, printed pp 4–5 and 14, leaves course/Unit 1 assessment decisions to schools. Queensland is the explicit alignment; do not relabel it as an approved course for another state or country without that jurisdiction's own crosswalk.