# Year 1 mathematics · Weeks 3–4 · 51 to 90

**Development draft, 29 September 2026.** Ten 25-minute lessons continue the [first fortnight](../weeks-01-02/README.md). Week 3 works through 51–70; Week 4 through 71–90. This is **partial** practice for Australian Curriculum v9 `AC9M1N01` and `AC9M1N02`: Year 1 reaches **at least 120**, and alternative partitions need later teaching. Follow the school's actual sequence and the entry evidence from Weeks 1–2. A child who still needs 0–50 should receive concrete teaching at that point, with age-respectful contexts and access to the shared discussion.

## Prepare and run

- Have nine reliable ten-strips (each visibly ten), ten loose counters, a labelled TENS/ONES mat, large digit cards, and the [original 51–90 chart](number-chart.svg) or [plain-text equivalent](text-alternative.md). Use paper marks, tactile strips or a learner-directed adult operator where loose pieces are inaccessible or unsafe. Audit that each ten-strip is ten before using it as one unit.
- Read the [ten scripts](LESSONS.md) and choose one of the three original [learner context cards](student-cards.md) for each day. The other two support later practice, home use or an unfamiliar recheck. Keep the [teacher key](teacher-key.md) separate from learner cards and [check sheets](student-checks.md).
- Teach the common 3 + 5 + 8 + 6 + 3 minute routine. Speak or show the number, build it, connect to a numeral/position, then ask the child to justify a comparison or exchange. A number chart can confirm an answer; it should not replace the concrete tens/ones reasoning when that is the target.
- Use the Day 5 and Day 10 checks as formative samples, with a **new** item for recheck. Record the response route and any conceptual prompt. Speech, sign, AAC, pointing, writing, drawing, tactile selection and adult movement directed by the learner can all show the target. Do not infer number knowledge from handwriting speed or speech alone.

The contexts are invented classroom models, not actual stock, routes or wildlife observations. No child needs to share family finances, language, health, culture or home circumstances. The teacher controls small-object safety and locally approved digital tools. Text is the complete alternative to the visual; no audio or translation is claimed.

## Source and rights

The two exact codes and level were checked against the [official ACARA Version 9.0 curriculum workbook](https://www.australiancurriculum.edu.au/downloads), retrieved 29 September 2026, SHA-256 `db446882d2c00cf7c085a03e250e2442fda6c44011fc114680c46c1dc7a822c3`. The [source and review record](source-and-review.md) gives the exact content-description scope and unfinished checks.

Original lessons, context cards, check sheets and vector chart © NeuroForgeIO Pty Ltd 2026, [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). Credit “SubjectNest by NeuroForgeIO Pty Ltd”, link the source and licence, and indicate changes. ACARA material remains under [its own terms](https://www.australiancurriculum.edu.au/copyright-and-terms-of-use); no endorsement is implied. Educator, accessibility, local-syllabus and classroom review remain pending.