CalcuDoku was invented in 2004 by Tetsuya Miyamoto, a Japanese math teacher. Two of the common names, Ken Ken® and KenDoku®, are registered trademarks of NexToy LLC.
Puzzle and Goal
An unsolved puzzle consists of a square grid with regions. Each region is marked with a small number and, in some puzzles, an operator; in other puzzles, the same operator applies to all regions.
The goal is to fill the cells with a Latin square.
The solved grid must satisfy the following conditions:
For each region, when the operator is applied to the numbers (in some order), the total is the clue shown.
Note: The same digit <em>can</em> appear multiple times in the same region, so long as the solution is a Latin square.
As a harder variant, operators are left out entirely.
Basic; Caldoku; Inkies; Kashikoku Naru Pazuru; Keen; Ken Ken; KenDoku; Kenko; MathDoku; Minuplu; Square Wisdom; Sukendo; Yukendo