Mathdoku + Calcudoku

Mathdoku + Calcudoku is arithmetic and logic puzzle similar to Sudoku and based on rules of Kendoku ® and KenKen ®

Fill the grid so that each row and column only have one of each available number (1 to N).
The table is separated into groups that are calculated together.
Each groups total is displayed in the top-left corner along with the operator that was used (+ * / - )
Digits may be repeated within a cage, as long as they arent in the same row or column.
The games are available in 6 formats: 4x4 (Beginner), 5x5 (Easy), 6x6 (Medium), 7x7 (Hard), 8x8 (Advanced) and 9x9 (Extreme)

Complete rules on http://www.essekappa.it?p=mathdoku