{"id":"fpa-rolling-12-month-revenue-lines","audience":"fpa","category":"finance-work","track":"finance","technique":"verification","level":"beginner","title":"Roll a 12-month revenue total forward by one month","free":false,"task":"You're updating the rolling 12-month revenue figure for the board deck. Write a prompt for plain text with lines starting \"Prior R12:\", \"Add Oct 2026:\", \"Drop Oct 2025:\", \"New R12:\" and \"Change:\", each with the math in $M. Change is shown in dollars and as a percent of the prior R12 to one decimal. Don't mention seasonality. Under 70 words. No bullets or numbering.","materialLabel":"Rolling revenue inputs (attached to your prompt automatically)","material":"ROLLING 12-MONTH REVENUE - Pinecrest Software ($ millions)\n\nPrior rolling 12 months (R12), the 12 months ended Sep 2026: $11.40M\nOctober 2026 revenue (the new month to add): $1.05M\nOctober 2025 revenue (the month that drops out of the window): $0.95M\n\nMethod: new R12 = prior R12 + new month - month dropped. Change = new R12 - prior R12, and percent change = change / prior R12.\n\nNotes: the finance director pointed out that October is usually a strong month, so the R12 'will be seasonally high'. Seasonality is not part of a rolling total; the window simply moves one month. The figures are recognized revenue.","rules":[{"type":"plainText"},{"type":"maxWords","max":70},{"type":"maxBullets","max":0}],"promptHints":[{"label":"Names the five lines","patterns":["prior r12","add oct 2026","drop oct 2025","new r12","change:"]},{"label":"Gives the formula","patterns":["prior r12 \\+","\\+ \\$1\\.05m"]},{"label":"Gives the percent base","patterns":["% of \\$11\\.40m","prior r12"]},{"label":"Bans seasonality","patterns":["(do not|don'?t).*seasonal"]},{"label":"Caps length","patterns":["\\d+\\s*words","plain"]}],"mistakes":[{"title":"Adding without dropping","why":"The AI adds October 2026 to the prior total and gets $12.45M.","fix":"Say: \"New R12 = prior R12 + new month - month dropped.\"","checks":["r1"]},{"title":"Mentioning seasonality","why":"The AI says October is seasonally strong.","fix":"Add: \"Do not mention seasonality.\"","checks":["r2"]},{"title":"Percent on the new total","why":"The AI divides the change by the new R12.","fix":"Add: \"Percent change = change / prior R12.\"","checks":["r2"]},{"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","maxBullets","r0"]},{"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 line short.","checks":["maxWords"]}],"hint":"A rolling total adds the new month and drops the oldest. State both and ban the seasonality comment.","rubricLabels":["The lines starting \"Prior R12:\", \"Add Oct 2026:\" and \"Drop Oct 2025:\" show $11.40M, +$1.05M and -$0.95M","The line starting \"New R12:\" shows $11.40M + $1.05M - $0.95M = $11.50M","The line starting \"Change:\" shows $11.50M - $11.40M = +$0.10M, which is 0.9% of $11.40M, and the output never mentions seasonality"]}