It’s Summer 1968. Christiane has turned six on May 20.
German School System
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(★) State schools combining Hauptschule and Realschule. They have different names in different states, for example “Sekundarschule”.
(★★) The Orientierungsstufe (grades 5 and 6) is differently implemented in the different states. Berlin and Brandenburg implement it as a part of the Elementary school. All the other states implement it as special conditions in the school types of secondary education during grade 5 and 6. Niedersachsen used to implement it as a dedicated school type, comparable to Middle School.