A vintage Aristo Studio slide rule, model 0968, made inGermany by Dennert & Pape.

This analog computing tool was widely used by engineers, scientists, and students in the mid-20th century (1950s to 1970s) before the widespread adoption of electronic calculators. Key Features of the Device Purpose: Performing complex mathematical calculations, including multiplication, division, trigonometric functions (sin, cos, tan), root extraction (sqrt x), exponentiation, and working with logarithms. Material: Made of high-quality white plastic (astralon), resistant to deformation. Design: Double-sided ruler (Duplex) with a movable slider in the middle and a transparent cursor with target lines for accurate reading of values. Markings on the body: ARISTO is a trademark. No. 0968 / Made in Germany is the model number and country of manufacture. DBGM (Deutsches Bundes-Gebrauchsmuster) is the German patent registration mark for a utility model. The original grey plastic protective case for storing the ruler is also visible in the background.