Course contents
Spreadsheets That Check Themselves
The assumptions-and-deliverables prompt pattern for financial models — including the checks tab that catches errors.
Claude builds real spreadsheets — live formulas, scenario dropdowns, dashboards — not pasted numbers. You can work in Cowork directly or inside Excel via the Claude add-in (Add-ins → search "Claude" → sign in with your paid account; the same skills and subscription follow you in). Either way, the prompt pattern below is what turns "make me a model" into a model you can trust.
Riley builds a full scenario-switching SaaS model with the exact prompt pattern below — and shows what a 15-minute autonomous run looks like.
Verify the connection with a tiny task
Riley's rule: "The first thing that you want to do is just make sure that it works." Ask for a one-sheet research summary or a small table before any big build.
promptOn one sheet, build a small table of our last 6 months of revenue from revenue-notes.md, with a total row and a simple line chart.VerifyThe sheet appears with correct numbers and a working chart.Write the assumptions block
List every input explicitly — this is the difference between a model and a guess. Numbers you specify are numbers you can defend.
promptBuild a fully dynamic 24-month operating model starting next month. Assumptions: 1,000 customers at $100/mo, 3% monthly churn, $400 CAC, 82% gross margin, $5M cash, 3 employees at $150K fully loaded, +2 hires per quarter, other opex = 18% of revenue.VerifyClaude replies with a build plan and asks to proceed rather than guessing at missing inputs.Write the deliverables block
Name the artifacts: scenarios, a way to switch between them, a sensitivity table, a dashboard — and crucially, a checks tab.
promptDeliverables: bear/base/bull cases with documented assumptions; a dropdown that switches the entire model between scenarios; a sensitivity table for runway under different churn and CAC; a summary dashboard; and a checks tab verifying beginning + new − churned = ending customers each month.VerifyThe plan includes all five deliverables. Reply "go" and let it run — 10–15 minutes is normal for a build like this.Interrogate the result
Flip the scenario dropdown and read what changes. Open the checks tab — every check should pass. Spot-check two formulas by clicking into cells: you should see real formulas referencing assumptions, not hardcoded values.
VerifyScenario switch changes the whole model; checks tab is green; formulas are live. If a run stalls or dies, rerun it or switch models — long runs occasionally fail, and that's recoverable, not fatal.