Split for discussion and join for sharing
As shown in the little math story, spliting the team in smaller groups can save you a lot of time in meetings.
There is two big ways you can use the split and join method.
First, you can have the same challenge for every group. That's great when you want a lot of ideas and then be able to decide which one is the best.
Or, second, you can give different challenges to each group. Then once they come back toghether you see how the different pieces come together. This makes it possible to get the preparatory work done quickly. You can then take more time to share a feedback elements to make the work of each group final.