This is a really simple plenary that takes no time to prepare – just write a load of keywords on a big whiteboard at the end of the lesson.
Two students come up and stand in front of the board – another student then asks a question whose answer is one of the keywords. The first of the two students to ‘splat’ their hand on the correct word wins. The keyword is rubbed off, the loser sits down, and the person who asked the question then comes up for the next round. Continue until there are no keywords left.
I haven’t done this for a while due to a lack of an accessible whiteboard – the board usually gets ‘splatted’ quite hard by the students so I’m not keen to try it with the interactive whiteboard. If you don’t fancy writing the keywords on the board yourself you can delegate this to students who have finished the previous task quickly – give them a few board pens and they’ll fill the board with keywords quicker than you could.