* Best viewed in Fullscreen mode * Count the boys - 13. * Click the inner circle to rotate it from A to B. Count the boys - 12. Which boy has vanished? Where did he go? (Click again to rotate back from B to A) I think of this puzzle as "The Disappearing Boy". Puzzles of this type are also known as "Get Off The Earth" puzzles. They are a type of Vanishing puzzle. Wikipedia: "Chess player and recreational mathematician Sam Loyd patented rotary vanishing puzzles in 1896 and published versions named Get Off the Earth, Teddy and the Lion and The Disappearing Bicyclist." https://en.wikipedia.org/wiki/Vanishing_puzzle
For the SDS studio "Puzzling Puzzlers" https://scratch.mit.edu/studios/51382117/ "Chess player and recreational mathematician Sam Loyd patented rotary vanishing puzzles in 1896 and published versions named Get Off the Earth, Teddy and the Lion and The Disappearing Bicyclist." https://en.wikipedia.org/wiki/Vanishing_puzzle
