Age group 4/5 years old
Two teams of 8 players: one team for clean waters and one team for dirty waters
"Find more fishes than 1/2/3 or 4 to put in the clean water" and "Find fewer fishes than 5/4/3 or 2 for dirty waters"
In this way, we've also formed the numerical scale.
Each team's member was applaud by his classmates for the answers and all children were very proud by their work.