Numbrix puzzles are the creation of Marilyn vos Savant, a feature writer of Parade magazine. Like similar number-placement puzzles, Numbrix puzzles rely on strategy. Unlike other number-placement puzzles, you do not need math skills or lots of guessing to complete a puzzle. The puzzle requires you to make an unbreakable path that allows you to count from 1 to 81 in a 9---9 grid.
Look at the numbers provided within the grid.
Select a number from 1 to 81 that does not already appear on the grid.
Insert the number you selected horizontally or vertically and in sequence to one of the provided numbers.
Insert additional numbers into the grid. The numbers you insert must be consecutive and form a horizontal or vertical path. You must be able to count from 1 to 81 without breaking the path.