May 24 - Medium/Hard © Kevin Stone

Auto pencil marks  Show a pinned square Show squares with a... 1 .2 ...3 ....4 .....5 ......6 .......7 ........8 .........9 Clear... Show errors Show duplicates Alternative highlights Warn when leaving page Pencil Marks: Simply enter multiple numbers per square. [Hide]   [Show Clock]

Notes

• Objective / Rules
  - Every row, column and 3x3 block must contain the digits 1 to 9.
  - Every cage has a little clue in the corner, and digits in each cage must add to the clue.
  - For example, a 2 square cage with an 11 clue could be 2 + 9, 3 + 8, 4 + 7 or 5 + 6 (either way around).
  - A cage does not contain the same digit more than once (which is different to CalcuDoku).
  - We have provided a page that shows possible combinations.
  - For more information please read the help page.
  
  
• Pencil Marks
  Enter a single number as an answer. Enter multiple numbers as pencil marks.
  
  
• Keyboard Usage [only when your cursor is in the grid]
  A = auto-pencil marks - be careful using this too early in the puzzle, as it will fill in each square with all remaining possibilities.
  P = show a pinned square.
  CTRL + arrows = move around the grid.
  SHIFT + number = highlight all squares with that number [SHIFT+0 to clear]
  
  
• Checking
  If you click 'Check' the system will tell you to use the 'Show Errors' option to check your solution.
  
  
• Uniqueness
  Each puzzle has exactly one solution, which can be found using logic alone and no guesses are ever required. If you think you've found another solution, then please double check the rules. If you still think you've found another solution, then please email us and we'll try to help.
  
  
• Combinations
  See all possible cage clues and combinations here.
  
  
• JavaScript
  This game requires JavaScript to be enabled.
  
  
• Help
  Read the help page on Killer Sudoku for a more detailed explanation and a walkthrough.