The breakdown didn't add up to the total

Spreadsheets

Situation: Summarizing a total count and its breakdown in a table or report.
What the AI did: It produced a table whose breakdown didn't add up to the total. It also didn't say whether anything had been counted in two categories at once.
How to ask next time (the operator's example): "Check that the breakdown adds up to the total. If anything is counted in more than one category, say so."
One question to ask: Is anything being counted in two categories at once?
Check it yourself: Add up the parts yourself and compare with the total. If they differ, ask which items sit in two categories, and how many.
AI used (month): Claude Code (2026-09)
Times this mistake was recorded: once
Source: The operator's work records (the details were changed to a different task)