I use these in my classroom to quickly divide kids in to different types of groups. You hand out the cards, tell kids which box on the card to look at, and then they find the partner or partners with matching cards.
This is great for Jigsaw activities.
Groups of 2 --> Star Wars characters
Groups of 5 --> Find the same number
Groups of 6 --> find the same color
Divide class into 4 groups--> Harry Potter Houses
Or divide the class in half by teaming up two of the houses
I usually cut these out and laminate them