For this game you will need a way to play music e.g. a bluetooth speaker and a phone or laptop.
Players stand randomly around the room/space.
Start to play the music and the participants can start to move around in any direction and in any way they want e.g. dancing, walking, jogging etc.
Every now and then stop the music and call out a number. Players must quickly join with people standing near them to form groups of that number.
Those children who cannot make up a group of that number, get together while the music restarts to choose the next number to be called.