The same can be said for every column, and every box. The numbers in blue represent the solution.Īs can be seen in the picture, every one of the 9 rows of the grid contains all numbers from 1 to 9 and, of course, no number is repeated. In the above example, the 1s form a conjugate pair, and the 2s also form a conjugate pair. If a candidate appears EXACTLY twice in a unit, then those two candidates are called a conjugate pair. The unsolved puzzle showed only the givens (the numbers in black). Simple Coloring, also known as Singles Chains, is a strategy that allows you to eliminate candidates by looking for contradictions. See the following puzzle solution for an example:

It follows that any single number may appear only once in the same row, once in the same column and once in the same box, or in other words no number may appear more than once in a row, in a column or in a box. Thus, it will be easier for you to track whether a figure is really found just once. Each box must contain all numbers from 1 to 9. When solving printed Sudoku, use different colors for each digit.Each column must contain all numbers from 1 to 9.Thats because we can apply the Rule of 45.

Each row must contain all numbers from 1 to 9. An easy way to find a starting point is by looking for a Region that contains multiple Cages and a single spare Cell.

The sudoku grid is composed of 9 rows, sometimes labeled 'A' to 'I', 9 columns labeled 1 to 9 and 9 boxes usually marked by heavier borders.Ī sudoku puzzle is solved when all the grid cells have been filled with numbers from 1 to 9 according to the following three rules: Color Sudoku and Sudoku Scrapbook are variations to the number game where the numbers are replaced by colors or pictures. This may be one of the reasons that make Sudoku so great. Although some Sudoku puzzles may keep us awake all night, the rules for solving them are very simple.

Color sudoku rules