Cross-My-Primes
Hello Math-Fun , this game (hope not old hat) is played on a kind of infinite Scrabble board where all squares are white, and no square has any text on it. The starting "star" square, in the center of the grid, has a 7 on it (the number, not the word, as this game is played with digits only that will form numbers – instead of letters forming words). The single player must now form prime numbers at every turn on the board – at the first turn placing the integer 1, at the second turn placing 2, then 3, then 4, then 5, etc. – this is the natural order of the positive integers as they appear (and because 7 starts the game, the player will jump from 6 to 8. No other jump will be allowed during the game). Those integers, as in the traditional game of Scrabble, must be attached to the existing structure at least by a digit (one digit per square). All visible numbers, before and after any turn, must be prime: they are read horizontally from left to right or vertically from