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Keywords from Image Description:
Fotothek df tg Geometrie Mathematik Arithmetik Rechenscheibe. Scan Deutsche Fotothek dftg color MIKCenter Berlin GmbH Frankfurt Main Rechenspiegel Papier Kupferstich cm Geometrie Mathematik Arithmetik Rechenscheibe ppn Druck Deutsche Fotothek gefrdert von der Deutschen Forschungsgemeinschaft Projekt Technikgeschichte Jh