Paper and pencil games

    Jumping numbers Players have to fill a 5x5 board as fast as possible with numbers from 1 to 25, beginning at a random position and then going from one square to another: jumping over 2 squares when traveling horizontally or vertically, jumping over 1 square when traveling diagonally.
    Some classmates and I used to play a lot of pen and paper games while sitting in the last row of the classroom. My favorite game was this one. We had to fill a 5x5 board as fast as possible with numbers from 1 to 25, beginning at a random position and then going from one square to another.
    

    Here is an example with numbers from 1 to 14 (it would be impossible to keep on filling the board, since 1, 13, and 8 are blocking the way)...
    Though this game is impossible with 2x2, 3x3 or 4x4 boards, it appears that NxN boards can be filled when N>4 (or n=1). For example, 6x6...
    

Free game on paper