Border Sum Sudoku
Rules
Fill the grid so that every column, every row and every 3x3 box contains the digits 1 to 9. The numbers at the border indicate the sums of the three first digit in that row or column.
Sample puzzles
EASY
MEDIUM
HARD
EVIL
All puzzles © by puzzlephil
Variants — Special Bordersum Sudokus
These Bordersum Sudokus have irregular and/or additional coloured regions.