excel-lessons

name: excel-lessons description: Write or revise a student-facing Excel lesson for Math for Business Operations. Use for lessons 4 or 5 to 6 when the lesson teaches a new Excel tool, workbook pattern, or automation move before project rehearsal. This skill is for business-pressure hooks, explicit tool anatomy, safe simulator practice, workbook build sprints, workbook audit/explanation, and reflection. Do not use for lesson 1 launch lessons, lesson 2 to 3 or 4 accounting-principles lessons, lesson 7 project rehearsal, or lesson 8-10 project lessons.

Excel Lessons Skill

Assume the repository's base lesson standard in AGENTS.md already applies. This skill adds only the Excel-lesson logic.

Goal

An Excel lesson should:

• teach one clear Excel move or workbook pattern
• connect that move to a real business decision or communication need
• rehearse the logic safely before students touch the live workbook
• produce a concrete workbook artifact by the end of phase 4
• check both tool mechanics and model trustworthiness

This skill covers the core Excel-build lessons, not the project rehearsal lesson.

Use This Skill When

Use this skill when the lesson's main job is to:

• introduce a specific Excel tool such as Goal Seek, Data Tables, validation, or lookup logic
• teach a workbook pattern such as scenario tables, dashboard summaries, or linked outputs
• build an investor-ready Excel artifact from prior accounting logic
• move students from conceptual math to applied spreadsheet automation

Do Not Use This Skill When

Do not use this skill if the lesson is mainly about:

• launching the unit story
• teaching an accounting rule or manual method before Excel
• auditing a shared rehearsal workbook before the project
• independent project production or milestone work

Use the separate project-rehearsal skill for lesson 7 style workbook audit and transfer lessons.

Core Writing Rules

• Teach one dominant Excel move per lesson.
• Start with business pressure, not software trivia.
• Name the starting workbook state and the ending workbook artifact explicitly.
• Keep the workbook logic tied to prior accounting reasoning.
• Rehearse the logic in phase 3 before the real workbook sprint in phase 4.
• Separate tool fluency from explanation and defense.
• Keep page, workbook, tutorial, and file names aligned.
• In phase 1, center investor or operator decision pressure, not a generic "fragile vs robust" contrast.
• In phase 2, require show-and-tell instruction: formula pattern, plain-language meaning, and why it works.
• If structured references are core to the move, include a decoder table that explains full-column vs row-level references.
• In phase 3, default to guided rehearsal of workbook logic over quiz-style multiple choice.
• In phase 4, prefer multiple sheet previews over one wide "all-in-one" reference grid.

Non-Negotiable Excel Rule

If the Excel procedure is fragile, multi-step, or easy to misconfigure, phase 3 must include a safe rehearsal component before phase 4 asks students to do the real build in Excel.

If workbook resources and page instructions diverge, fix the resources. Lesson pages are not complete until workbook and tutorial match the same build sequence.

Excel-Lesson Phase Contract

Phase 1: Tool Pressure

Purpose: Create business urgency for the tool or workbook move.

Requirements:

• open with a business or investor scenario where speed, clarity, or flexibility matters
• make the tool feel necessary, not decorative
• connect the lesson to the existing workbook or model
• include one short comprehension or discussion move
• frame the hook around concrete decision questions stakeholders will ask

Avoid:

• feature lists without business context
• generic "Excel is useful" exposition
• overusing before/after "fragile vs robust" framing as the main storyline

Phase 2: Tool Anatomy

Purpose: Teach the feature mechanics, the required inputs, and the common setup traps.

Requirements:

• name the tool or workbook pattern clearly
• explain the parts of the feature directly
• show where the tool lives in Excel when relevant
• include one short check on vocabulary, anatomy, or setup logic
• teach at least one common failure mode
• explicitly decode the formulas students will build (show formula, explain meaning, explain why)
• include structured-reference interpretation when table references are central

Avoid:

• discovery-first tool instruction
• skipping prerequisites from the existing workbook
• relying only on fill-in-the-blank or vocabulary checks when formula decoding is the real need

Phase 3: Safe Rehearsal

Purpose: Practice the logic in a no-risk environment before students touch the live workbook.

Requirements:

• use a custom simulator, manual logic trainer, or tightly bounded guided interaction
• mirror the real workbook logic as closely as possible
• give immediate feedback or reveal after an attempt
• make the bridge to phase 4 explicit
• include at least one explanation step where students translate formula logic into plain language

Avoid:

• using only prose when the tool setup is fragile
• broad sandbox interactions
• a rehearsal task that does not match the phase-4 workbook move
• turning phase 3 into a primary multiple-choice assessment when build-readiness is the goal

Phase 4: Workbook Sprint

Purpose: Build the real Excel artifact.

Requirements:

• state the exact starting workbook or download path
• state the output students should finish by the end of class
• include one reference model or layout guide
• provide a short build sequence with no more than a few major blocks
• include verification checkpoints after major build steps
• include a Definition of Done or rubric
• keep reference layout readable on page (split by workbook tab/sheet when needed)
• ensure tab names in page instructions match workbook tab names exactly

Avoid:

• assuming prior workbook success without naming a fallback or checkpoint
• giant instruction dumps with no verification gates
• workbook tasks with no visible deliverable
• single ultra-wide reference grids that force horizontal scanning across unrelated logic blocks

Phase 5: Audit and Explain

Purpose: Check tool understanding and require a brief workbook-based explanation or defense.

Requirements:

• use a short technical or conceptual check
• add one brief artifact task such as a memo, voice script, recommendation, or audit response
• focus on trustworthiness, interpretation, and business communication

Avoid:

• bloated assessments
• turning phase 5 into a second build sprint

Phase 6: Reflection and Handoff

Purpose: Lock in what the tool added to the model and preview the next workbook layer.

Requirements:

• reflect on both tool use and professional judgment
• name what the student can now do faster or more reliably
• preview the next workbook layer or next lesson's build

Avoid:

• major new instruction
• long repetitive recap sections

Spreadsheet Component Rules

SpreadsheetWrapper is a preview component first, not a full Excel engine.

Use SpreadsheetWrapper when you need:

• a reference layout
• a static workbook mockup
• a simple read-only model preview
• a small controlled spreadsheet interaction with tested formulas

Do not rely on SpreadsheetWrapper for:

• modern Excel-only formulas such as XLOOKUP
• authentic formatting plus live computation in the same cells
• chart wiring, dropdown validation behavior, or workbook QA workflows
• the main practice loop for a fragile Excel procedure

Spreadsheet Authoring Rules

• Treat any cell value that starts with = as a live formula.
• If a formula should be displayed as text, prefix it with a leading space.
• If a formula should actually calculate, referenced inputs must be raw numbers or plain numeric strings, not currency-formatted strings like $1,350 or labeled strings like 24 units.
• Most lesson reference sheets should use precomputed outputs and formula-text-as-text.
• Use explicit cell factory helpers for consistency.
• Build rectangular grids with explicit blank cells instead of ragged rows.
• Pass explicit columnLabels for reference models.
• In read-only previews, set both cell-level readOnly: true and wrapper-level readOnly={true}.

Formula Guidance

Under the current component stack:

• IFERROR and other simple functions may work
• XLOOKUP should be treated as unsupported in SpreadsheetWrapper
• currency-formatted strings will break arithmetic formulas
• formula parse failures often collapse into generic spreadsheet errors

Therefore:

• only use live formulas in SpreadsheetWrapper when the exact parser behavior has been tested
• otherwise show formulas as text and show the expected outputs separately

Recommended Cell Helper Pattern

Prefer local helpers such as:

• blankCell
• textCell
• numberCell
• formulaTextCell
• headerCell

formulaTextCell should store displayed formulas with a leading space so the wrapper does not execute them.

Simulator Rules

Phase-3 simulator components should:

• mirror the real workbook move
• expose the key input, target, and output relationship
• include one or two common errors
• give immediate feedback
• end with a clear handoff to the actual workbook
• prioritize guided walkthrough and explanation practice over point-scoring

If students need feedback, gating, hints, retries, or deliberate practice, use a custom simulator component instead of trying to make SpreadsheetWrapper do everything.

Workbook Continuity Rules

Every Excel lesson should define:

• the required incoming workbook state
• the file students should open or download
• the exact sheet, block, or artifact they will build
• the short evidence they will carry into phase 5

If the lesson depends on earlier workbook work, provide a checkpoint workbook, a fallback download, or a clearly named minimum starting state.

Resource Parity Checklist

Before finalizing an Excel lesson revision, verify:

• phase pages, workbook tabs, and tutorial steps use the same sheet names and order
• sample checkpoint numbers on pages match teacher workbook outputs
• student workbook scaffolds exactly what phase 4 asks students to build
• teacher workbook demonstrates the exact formula architecture described in phase 2 and phase 3
• phase 4 reference previews are organized by sheet when the model is multi-sheet

Assessment Scope Note

If the user or track specifies that quality controls (validation, naming, error handling) are cross-unit norms:

• mention them as professional expectations
• do not make them the primary scored target for the lesson

What Not To Standardize From Unit 6

• mismatches between page content and tutorial/workbook sequence
• reference sheets that accidentally execute unsupported formulas
• phase-4 pages that assume the prior workbook is already perfect
• assessments that sprawl into a second full build task

Success Test

A strong Excel lesson should leave students able to answer:

• What business problem does this Excel move solve?
• What workbook inputs or prerequisites does it depend on?
• What are the exact build steps?
• What common setup error should I check first?
• What workbook artifact proves I completed the lesson correctly?
• How would I explain the result to a teacher, investor, or teammate?