Hiring tradespeople

Two things are multiplied in Pi mal Daumen: pi, the most exact number anyone met at school, and the thumb, the crudest ruler anyone carries. Mal is the ordinary word for times, as in drei mal vier, so the phrase reads pi times thumb, and the joke lies in the product: precision multiplied by guesswork is still guesswork. It means roughly, at a rough guess, what English calls a ballpark figure, and it belongs to speech, never to a letter. On a building job it marks a line worth hearing. A tradesman who says Pi mal Daumen zwanzigtausend at the front door has promised nothing; what binds him is a verbindliches Angebot or a Pauschalpreis on paper. The rest of this list is what happens once the thumb has been put away: deadlines, defects, and who pays for them.