For those of you who want to improve your success at gaining control back to class after group activities, I have attached a 60-second countdown powerpoint. This was readily available on one of the TES forums some time ago and I often use it if I want to increase classroom learning activities but when time-wasting is not an option. Use a 5-minute and 2-minute verbal ‘warning’, then the 60 seconds should be just enough time to bring things to a close. Please feel free to use and share this document.
Alternatively, you could try using egg timers for those groups who'd prefer to manage their own time.
Click here >>> 60_second_countdown to download into a new window.