Some Indigenous Central Australian mobs organised their communities into skin groups.
Skin Groups are systems of organising smaller clans of people so as to avoid inbreeding, delegate roles and responsiblities, in addition to cermonial activites and land.
This activity involves students in a table group, or whole groupings of students, in a class to pick one of the 8 skin groups cards. Students must then organise with the other skin groups to figure out who they can marry. Once this has been figured out, students must then attempt to figure out what skin groups produce other skin groups.
For more information Wikipedia has a thorough entry describing the practice: