Grade 8 — Time Machine for My Work

Big idea: every file has a history, and you can go back. Length: ≈ 12 periods (calibrate to CDC hours — unverified). Accounts: none; everything stays on the school computer (students may be under 13). Tools: paper and cards (Tier 0) · Git + VS Code or GitHub Desktop, and the self-hosted Learn Git Branching visualiser (Tier 1+). Hooks: file management, digital literacy, basic statistics.

How this chapter is built

Grade 8 is the foundation of the whole book. Students meet one mental model — a commit is a snapshot of the whole project, with a message, that points to its parent — first on paper, then on a computer. Everything in Grades 9–12 (branches, remotes, pull requests, CI, internals) is built on that picture, so take time here.

 M1  why?               (paper)
 M2  snapshots          (paper cards)
 M3  first repo         (GUI)
 M4  read history       (diff)
 M5  undo               (safe undo)
 M6  statistics         (maths link)
 M7  project            (own work)

Modules

#	Module	Periods	Tiers	Key commands / actions
1	The final_final_v3 problem · teacher guide	1	0–3	— (unplugged)
2	Snapshots = commits · teacher guide	2	0–3	paper commits
3	My first repo · teacher guide	2	1–3	status, add, commit
4	Reading history and comparing versions · teacher guide	2	0–3	log, show, diff
5	Undo and restore · teacher guide	2	0–3	restore, revert
6	Statistics: chart my commits · teacher guide	1	0–3	log --format
7	Mini-project: Class Magazine · teacher guide	2	0–3	everything

Printable materials: cards, Parsons strips and badges.

Chapter outcomes

By the end, a student can:

1. explain why keeping many copies of a file by renaming is risky;
2. explain a commit as a saved snapshot with a message;
3. create a repo, make commits, and read the history;
4. compare two versions and say what changed;
5. restore an earlier version of a file and undo a commit safely;
6. present a bar chart of their own commit counts.

Free resources used in this chapter

All Grade 8 exercises work without an account. The main ones: Learn Git Branching (self-hosted copy for offline labs), Software Carpentry's git-novice episodes 1, 4 and 5 (CC BY, may be printed), Pro Git chapters 1–2 (link only), and the VS Code Source Control docs. The full list with licences is in the free resource library.

Assessment

• Exit tickets in every lesson.
• Commit-history rubric: ≥ 5 meaningful commits, each message says what and why, no commit larger than one idea.
• Oral explanation (2 minutes): "show me how you would get yesterday's version back."
• Board-style item bank: assessments/g08-item-bank.md.

Capstone

Class Magazine: each student keeps one article's history; the class exhibits the "evolution" of an article. Practice repo: practice-repos/g08-class-magazine/.

Ready for Grade 9?

A student is ready when they can, without help: make three commits with good messages; find who/when/why for a change; and choose between restore and revert. Students who cannot yet should repeat Modules 3–5 with a buddy at the start of Grade 9 (the bridge course also covers this).