Connect four game for pupils to do in pairs or groups of four (with two teams of two pupils). In my experience the activity works best when the board is laminated and pupils can use whiteboard markers.
Pupils take it in turns to try and answer a question, and are peer assessed by the other team. If they get it correct they can put their initials over the space, and the goal is to get four squares in a row. The pupils could also used colour post it's or counters.