If you like Sudoku, this is the next step in number riddles from Japan. All you need for a challenging game
- Easy rules,
- Levels from very easy to ultra-hard.
- Very easy user interface
- With all the help an app can give you, but not more
- No useless menus, graphics, sound or music

MathDuko rules:
Fill the grid with digits (1, 2, 3,...) so that in the rows and columns every number appears only once and in every row and column and in the red outlined clusters the target number is produced, using the operator (addition, subtraction, multiplication, or division) shown in the cluster.
Examples for a 5x5 field:
Clusters with 2 numbers:
3+ -> 1, 2
5+ -> 1, 4 or 2, 3
5* -> 1, 5
3÷ -> 3, 1 or 1, 3, sequence is not relevant
4- -> 5, 1 or 5, 1, sequence is again not relevant
Clusters with 3 numbers:
15* -> 1, 3, 5
10+ -> 5, 4, 1 or 5, 3, 2
If a cluster is not in a line, the same number can appear multiple times in the cluster

I would be happy to get new proposals or improvements and will try to implement them into the app. If you like my app, please write a nice comment. Then I still wish much fun by solving new riddles again and again.