Select a structure such as a tent that is difficult for one person to assemble on his own. Give the children directions, and assign them to groups of two or three. Have them assemble the tent or other structure as quickly as possible. This activity also can be done as a race against other teams.
Telephone is a game familiar to many children and adults alike. The game involves having one child whisper a message into the ear of another child, who repeats the process down a line of a handful of other children. The goal is to relay the message exactly as intended from the first child to the last, meaning that all of the participants will have to work together to avoid errors.
Shape drawing can be made into a synergy game between two children. One child is given a shape on a piece of paper, which the second child is not allowed to see. The second child has a paper and pencil to use to draw the shape according to the first child's instructions.
Divide children into small groups with pieces of a jigsaw puzzle. On one side should be the picture the children are trying to assemble and on the other side should be instructions for a task to complete. Once the children finish assembling the puzzle, they can flip it over and read the task they are required to complete as a team.