Addiator ... I have one, from Professor Adolf D. May, Jr. | Old calculator, Slide rule, Pocket calculators
Vintage tech: the Addiator : r/calculators
Piccolo-S addiator calculator - MAAS Collection
File:Vintage Arithma Addiator Mechanical Handheld Calculator, Made In Germany, Variants Were Produced From 1920 - 1982, This Calculator Was A Promotional Item For Ser-Ap-Es (21295273712).jpg - Wikimedia Commons