Invented in 19 century, Number Puzzle is a classic sliding puzzle that consists of a frame of numbered square blocks in random order with one block missing. The objective of the puzzle is to place the blocks in order by making sliding moves that use the empty space.
Play on 4×4, 5×5, 6×6 tile boards
Number Puzzle is also known as Sliding Block Puzzle, Game of Fifteen or 15-puzzle.