The siblings Anna and Tim want to share a Christmas stollen and divide it into two fair pieces. The Christmas Stollen has an irregular shape so that the middle is not immediately recognizable. What is the best way to proceed so that everyone gets a piece with which they do not feel disadvantaged?
Solution: Each of them makes a notch in the gallery where they think half of the cake is. This is a purely subjective sensation. But since both Anna and Tim are convinced that their notch will divide the cake in the middle, they would agree with each of their two halves, no matter if left or right of their notch. Finally, let's cut in the middle between the two notches and everyone gets the part of the Christmas cake where their notch is. This way both of them even get the feeling that they get more than half of the stollen if the notches are different.