Kakurasu Solving Tips
Kakurasu is pure arithmetic: a few forcing patterns do nearly all the work. New here? Read the rules first.
1. Zeros and full lines
A 0 total: cross every square in that line. The maximum (1 + 2 + … + n, so 15 on a 5×5): fill every square.
2. Small totals
A row total of 1 means only column 1 is filled. A total of 2 means only column 2 (not 1 + 1, since each square counts once). Totals of 3 have two options: column 3 alone, or columns 1 and 2.
3. Too heavy to fit
If a row's remaining total is 4, columns 5, 6 and 7 are too heavy: cross them. Do this in both directions and the grid thins out quickly.
4. Nearly full lines
A total one short of the maximum means exactly column 1 is empty; two short means only column 2 is empty. Work out which single square is missing.
5. Cross-check
Every square belongs to a row and a column. When a row forces a square, add its row number to that column's running sum and see what the column still needs; the answer often forces the next square.
Frequently asked questions
Where should I start a Kakurasu?
At the extremes. A total of 0 means an empty line; the maximum total (1 + 2 + … + n) means a full line. Then look for totals of 1 or 2, which pin down single squares.
Last updated 2026-10-20