This card sort activity provides students with several examples of relationships, presented in various representations. Students are to sort the cards into two groups - Functions and Not Functions. The intention is that this would be one of the first activities done in a Functions unit. Students would revisit their sorting at the mid-point of the unit and again at the end of the unit to discuss with a small group if there are adjustments that should be made to their sorting. The activity includes student directions and a total of 12 relationships to be sorted.