What Is Kakuro (Cross Sums) - Solving Kakuro Puzzles
Mathematics of Kakuro - Kakuro Variations - Links
Like Kakuro? Try Sudoku!

Kakuro Variations

A relatively common variant of Cross Sums is its logical successor, Cross Products (or Cross Multiplication), where the clues are the product of the digits in the entries rather than the sum. Another variant is Arrow Numbers, where the combinations for each clue value cannot be repeated within the grid.

The final puzzle of the 2004 United States qualifier for the World Puzzle Championship is titled Cross Number Sums Place: it is a Cross Sums where every row and column of the grid (except the top row and leftmost column as usual) contains exactly nine white cells, none of which - even across multiple entries - are allowed to use the same digit twice, like a Number Place (Sudoku); in addition, small circles are printed on the borders between some white cells; numerically adjacent digits must be placed astride those circles, and may not appear orthogonally adjacent when not astride a circle.

Didn't Find What You Were Looking For? Try Google!