Icebreaker

I'm working group with children 12-16 years tomorrow. They all know each other but I still want to have an icebreaker. Ideas?

What ..... polar bear 7 tons if it does not break any ice

were all wearing lapel badges with their names on.

Tell them your name, then ask them one at a time it was theres.

Are you sure you can have an ice breaker with people who know each other ?????
We learn something new every day ... Thank you. !

What if you played a game where everyone is in a circle and a point person, but to say there own name is really confusing and if they say that people not there then they should sit and who earns more they get a prize but a good laugh

Get some ice, through it on the ground before them, stomp on him and say: "Well now that the ice was broken" and from there.

How about lemonade, chips, cakes, etc., food or snacks are a great way to break down barriers.

You do not say what kind of group work (arts or music) you attack. I guess breaking the ice is between you and the group rather than in the group itself, because they know each other. Even if there is an age gap and the skills and attitudes may vary between 12 and 16 years old wildely children. Although they know each other, they may have very different abilities and tastes, so I see your problem. After introducing yourself, you could tell a funny story about an experience you had around that age to make them laugh. It need not be entirely true, but it would break the glass. You might ask what their favorite music / band and divide them into groups with similar preferences. Otherwise, you can play a little bit of something special, a CD or an instrument, and ask them what they think and how they rate and why. That should make it even less confidence ..