Curriculum units

A curriculum unit teaches one concrete, reusable concept. It should be small enough to have clear prerequisites and combine into different learning paths, yet complete enough to be a self-contained microlesson for a learner who has mastered those prerequisites. It is neither a broad chapter nor a thin outline. Write the unit's canonical name and content in English. Other languages belong to the translation layer rather than the canonical curriculum source.

Give each unit a clear educational responsibility. Before creating one, search the published curriculum carefully for the concept and closely related units. Do not create a duplicate or a partially overlapping alternative. If candidate units overlap, find the conceptual boundary that gives each one a distinct purpose; if several branches need the same knowledge, reuse one shared unit.

Use Writing content for the editorial quality contract and Dependencies to represent what the learner must already know.