Custom Worksheets — Coordinate Geometry Stage 2

Custom Worksheets — Coordinate Geometry Stage 2

Version: 0.2.0
Date: 10 September 2026

What changed

Stage 2 keeps the Stage 1 coordinate IDs stable and extends the same deterministic visual engine after reviewing additional Corbettmaths, MathSphere and historical KS2 coordinate material.

Normal curriculum-facing families

• coordinates_y4 — 12 stable subtypes / 72 pool entries
• transformations_y5 — 9 stable subtypes / 54 pool entries
• coordinates_y6 — 18 stable subtypes / 108 pool entries

New structures include labelled-point lookup, same-displacement endpoint reasoning, reflected coordinate sets about offset axis-parallel mirror lines, four-quadrant plotting-error diagnosis, plot/join/name construction, kite completion, reflection sign reasoning and four-quadrant reflection-pattern completion.

Explicit extension family

coordinates_extension — 4 stable subtypes / 24 pool entries:

• midpoint from two endpoints;
• centre of a rectangle;
• equally spaced points on a coordinate line;
• 90° point rotation about a centre.

These are deliberately separated from the normal Year 4–6 families. Their presence in historical/booster material is useful for worksheet variety but is not treated as authority to widen the normal statutory coordinate selection.

Custom Worksheet workflow change

The Custom Worksheet now starts with zero topics selected. The former Year 1–6 and Core 4 quick-select row is removed. Teachers can select any combination of curriculum families manually, clear one category, or clear all selections. The optional Year generation profile adjusts age-sensitive number/range behaviour only and never chooses content.

Accordion state is explicit: selecting/deselecting a topic does not collapse its category, and selected categories do not auto-open after a teacher closes them.

Architecture

• Coordinate maths and SVG/PDF drawing remain isolated in assets/99club/custom-coordinates.js.
• Shared visual page packing remains in assets/99club/custom-graphs.js.
• custom-graphs.js no longer observes or rewrites the Custom Worksheet DOM; UI copy is owned by custom-app.js.
• Blank family-mix rules are now a valid editing state in generator.js; public 99 Club fixed-seed generation remains unchanged.

Source policy

The source sheets are used to identify mathematical structures and pupil actions. Wording, artwork and page layouts are not copied. Statutory/project curriculum mapping remains the authority for normal year-facing families. Historical/booster-only structures are kept separate where appropriate.