The quick read
- Calculate one example by hand and compare it with the sheet.
- Separate inputs from calculations and label assumptions.
Define the calculation
Explain each input, its unit and the intended output. Decide how missing values, dates and rounding should be handled. A valid formula can still be inappropriate if it uses the wrong business assumption.
Test simple cases
Calculate one example by hand and compare it with the sheet. Include zero, a missing input and a boundary date where relevant. Inspect cell references and confirm that copied formulas change in the intended way.
Keep the logic inspectable
Separate inputs from calculations and label assumptions. In a project-cost sheet, show rates, hours and fixed charges rather than hiding them inside one expression. Recalculate using a compatible spreadsheet engine before trusting displayed values. Ask AI to explain a formula and suggest edge cases, then check those explanations. A screenshot is not evidence that a workbook calculates correctly. The useful outcome is a sheet another person can inspect, update and understand without reverse-engineering its hidden logic.
Sources & notes
AI-assisted editorial content checked against the linked sources.
developers.openai.com — official reference
Sources reviewed for the September 2026 launch edition.