Check these teenagers out!
In the island of Sardinia, most every male can play this traditional game of Morra:
it is played by two 2-man teams. As you see in the video, the 2 duos stand in front of each other, while each player ( at an incredibly fast rythm) throws numbers with one hand, while enunciating the number he guesses to be the sum of his fingers and his opponent’s (in strickt Sardinian dialect/language). The same 2 opponents keep going until either one guesses the correct sum. He then, without skipping a beat and without forgetting to tease his opponent with a personal exclamation, moves to challenge the other opponent.