The author presents a fun math puzzle involving the use of four instances of the digit 2 to create any target natural number through various mathematical operations. The puzzle can be enjoyed by individuals of all math skill levels, from elementary school kids to university graduates. The challenge becomes more complex as you consider using advanced mathematical tools like the Gamma function or complex numbers. While mathematicians in the 1920s enjoyed this puzzle, Paul Dirac later found a general solution for every number using nested square roots. However, with a slight modification, the puzzle can still be solved using only reasonable math operations. The author credits Graham Farmelo’s book for introducing them to this fascinating puzzle.
https://eli.thegreenplace.net/2025/making-any-integer-with-four-2s/