How to play
Fill every row and column with 1 to n, no repeats. Each bold-bordered cage must combine — using the operation shown — to reach its clue number. A cage with a single number and no symbol just needs that value.
On 8×8 and 9×9 boards the generator does its best to keep the solution unique within a short time budget; on rare occasions a very large puzzle may admit more than one valid solution.