The case in three lines. Tara's front-page story in the Green's volunteer paper says a new crossing will cost £240,000. A reader writes in: the council minutes say £24,000. Tara's first instinct is to fix the website quietly; instead, with Attest, Deed and Widen, she finds that the number came from a campaign flyer, checks the original minutes, and sees that the real cost is about 8% of a year's roads budget rather than three quarters of it. The editor, afraid a correction will cost the paper its readers' trust, hands Tara the pen, and the case stops there.

One question to ask. "What was the first line of Tara's correction?" Then: "Who in this story was trying to protect something?" Everyone was.

One thing to do at the table. Find one number in today's news, a price or a percentage, and ask two questions about it together: who says so, and compared with what?

The grown-up layer. The case is about the open correction: saying publicly what was wrong, what is right and where the error came from, instead of changing the record quietly. It also models two everyday checking habits, going to the original document and putting a number beside a comparison. Mrs Hallam's fear is a real one in small newsrooms; the case gives her the strongest version and still leaves the decision to Tara.

The case leaves the correction blank on purpose. Ask for it before you offer yours.