National Institute of the Republic of Serbia
ὅδε οἶκος, ὦ ἑταῖρε, μνημεῖον ἐστιν ζωῶν τῶν σοφῶν ἀνδρῶν, καὶ τῶν ἔργων αὐτῶν
The mechanical calculator (popularly known as “mućkalica” or “churner”) produced by the TRS Zagreb Factory in the mid-20th century was a vital tool for performing arithmetic operations, including addition, subtraction, multiplication, and division. TRS (Tvornica Računskih Strojeva) Zagreb, a leading Yugoslav manufacturer of calculating machines, designed these devices to address the growing need for precise computation in offices, schools, and scientific institutions during the pre-digital era. Operated manually via levers and cranks, they were extensively used in accounting, engineering, and administrative tasks, providing reliable results long before electronic calculators became standard. The historical significance of these calculators extends beyond their role in modernizing computation in Yugoslavia. They were instrumental in education, particularly in the 1970s, when they were used for exercises in Numerical Analysis I and II, taught by Professor Konstantin Orlov with assistant Arif Zolić at the Faculty of Science and Mathematics in Belgrade. These courses, part of the Numerical Mathematics and Cybernetics major, equipped students with foundational skills in mathematical computing.
Creator: TRS Zagreb Factory, 1950-1960
Source: Mathematical Institute SASA
Text prepared by Dragan Blagojević, Cvetana Krstev
Photo by Dragan Aćimović
