Mit barer Münze

This is based on a game played by the Ancient Greeks and Romans. A clock-shaped field with numbers 1 to 12 and 15 coins are the materials to play this game. Get the least penalty points by "rolling" the coins in the air and seperate the coins in two groups: one with a number from 1 to 15 revealed and the other with a face revealed. Place the coins with numbers on the field by using their own number, sum of two coins or difference of two coins. If you can't place any coins anymore, throw the coins up again and start over, until you can't place any coins of your throw. The sum of your coins you couldn't place are your penalty points.