“Significant Figures”

A touring lecturer started off his favorite lecture: ‘A million years ago this earth was trod by dinosaurs.’ He was immediately interrupted by a well-meaning old lady in the audience, who said, ‘You mean a million and eight years ago, don’t you?’ ‘Why do you say that?’ queried the lecturer. ‘Because I heard you give this same lecture eight years ago,’ explained the old lady.

— Howard Eves, Mathematical Circles Revisited, 1971