{"id":"acct-customer-statement-balance-forward-lines","audience":"accounting","category":"finance-work","track":"finance","technique":"verification","level":"intermediate","title":"Build a customer statement summary and keep a later payment out","free":false,"task":"You're preparing the October statement for a customer. Write a prompt for plain text with lines starting \"Opening balance:\", \"New invoices:\", \"Payments:\", \"Credits:\", \"Closing balance:\" and \"Note:\". Show the math. The Note line mentions any item that is not on this statement, without changing the balance. Under 90 words.","materialLabel":"Source material (attached to your prompt automatically)","material":"CUSTOMER ACCOUNT - Westbrook Co\nStatement period: Oct 1 to Oct 31, 2026\n\nBalance at Oct 1: $8,000\nInvoices:\n- INV-5001 dated Oct 3: $5,000\n- INV-5019 dated Oct 17: $7,500\nPayments received:\n- Oct 12: $9,000 (check)\nCredit memos:\n- CM-31 dated Oct 20: $1,500 (returned goods)\n\nAfter the period:\n- Nov 1: payment of $2,000 received by ACH. It will appear on the November statement.\n\nNotes: the customer's AP contact, Priya Raman, called on Nov 2 and asked why the statement does not show the Nov 1 payment. Statements show activity within the statement period only. Closing balance = opening balance + new invoices - payments - credits. The statement is sent by email on Nov 3 and the same figures are used in the AR aging at Oct 31.","rules":[{"type":"plainText"},{"type":"maxWords","max":90}],"promptHints":[{"label":"Names the six lines","patterns":["opening balance","new invoices","payments","credits","closing balance","note"]},{"label":"Gives the formula","patterns":["opening","- payments","- credits"]},{"label":"Limits to the period","patterns":["oct 1","oct 31","period"]},{"label":"Notes the later payment","patterns":["nov 1","later","not on this statement"]},{"label":"Caps length","patterns":["\\d+\\s*words","under \\d+"]}],"mistakes":[{"title":"Subtracting the Nov 1 payment","why":"The AI shows a closing balance of $8,000.","fix":"Say: \"Only activity from Oct 1 to Oct 31; mention later payments in the Note.\"","checks":["r1","r2"]},{"title":"Sign errors","why":"The AI adds the credit memo.","fix":"Add: \"Closing = opening + invoices - payments - credits.\"","checks":["r1"]},{"title":"Missing labels","why":"The AI writes a table.","fix":"Add: \"Six lines with these exact labels in order.\"","checks":["r0"]},{"title":"Markdown extras","why":"The AI adds bold labels, headings and a closing note.","fix":"Say: \"Plain text, no bold. Output only the lines asked for.\"","checks":["plainText"]},{"title":"Trusting the AI to count words","why":"AI is bad at counting and runs past word limits.","fix":"Ask for fewer words than the real cap and keep each part short.","checks":["maxWords"]}],"hint":"A statement shows one period. State the formula and put anything outside the period in the Note.","rubricLabels":["The six lines start Opening balance:, New invoices:, Payments:, Credits:, Closing balance: and Note: in that order","New invoices shows $5,000 + $7,500 = $12,500 and Closing balance shows $8,000 + $12,500 - $9,000 - $1,500 = $10,000","The Note says the Nov 1 payment of $2,000 is not on this statement (it will appear on the November statement) and the closing balance is not reduced by it"]}