Run up to 20 Excel-style scratch formulas against a native spreadsheet without writing anything. Optional input overrides support what-if analysis without changing the user’s cells. Uses the same IronCalc engine as the editor and returns typed results/errors. ReadSpreadsheet first to learn sheet IDs and ranges. Unqualified references use sheetId. Each formula evaluates at A1 on a private sheet and returns its top-left value; position-sensitive functions such as ROW() therefore use A1. INDIRECT is not supported in scratch formulas. Use this to verify totals, test a proposed formula, or compare scenarios before editing. Volatile functions are disabled, as in the editor.