This activity can be used as a card sort for naming simple hydrocarbons (unbranched alkanes, alkenes, alkynes). My original intention, though, was a game/contest: I give each student a card and have them match with the corresponding name/ structure (I participate if an odd number of students). I time how long it takes my students to do this (twice- I switch their cards for the second trial). Whichever of my classes does it fastest earns something like no homework or bonus points