@th Thought of this yesterday when somebody was showcasing a card game with reflection questions and one of them asked »was war Deine größte Lehre im vergangenen Jahr« (what was your biggest lesson learned in the past year), with the ambiguity that »Lehre« (lesson learned) is also the word used in »Schieblehre« (slide rule).
I guess for you the answer to that card would have been clear!
I remember this kind of things (at that scale): They were used in school by the teachers to demonstrate how to use a *Rechenschieber* (this how it is called in German language).
@th A sliderule that size is clearly used for
long division