Time needed: 2 – 5 min
Why? To find out what students know about the new topic and to make students interested in the new topic.
When? Any time when you want to introduce a new topic. Those quizzes are enjoyable and students like to do such games and its a good possibility to evaluate their foreknowledge.
How? Just collect some questions connected to the new topic and form a quiz. Don’t forget to reward winners.
Any risks? There is no real risk, the time frame is clear based on your preparation, also you will be surprised what students know about new topics already and also not just only the same students, it the chance for everyone to show what they know already.