Sudoku Variants Series (418) - Sum and Product Killer
(Published on 4. April 2025, 12:00 by Richard)
Logic solvable
Sum and Product Killer
Inspiration for this type comes from PixelPlucker.
Solve online in Penpa+ or in Sudokupad.
Like all of my sudoku variants, this puzzle can be solved by logic alone. Guessing is not required and also no sophisticated solving techniques are necessary; just plain and easy sudoku steps and of course the intrinsic logic this specific variant has to offer. In case you don't find that logic or get stuck, feel free to ask for a hint in the comments below this puzzle and I'll be happy to help you.
Apply classic sudoku rules.
The small numbers in the upper left corner of each cage (dotted outlined region) indicate the sum of the digits in that cage. An X between cells indicates that the two adjacent digits are multiplied when calculating the cage total. (For example: 14 can be formed by the digits 4x3+2 or 9x1+5.) Within each cage all digits must be different.
Solution code: Row 1, followed by row 9.
Comments
on 17. December 2025, 20:23 by dzamie
Glad I came back to this one! It took me only about an hour (which is by far the fastest I've solved a 4*). I think the large 69 cage scared me away before, but seeing that it's 9 cells in size made it a lot more approachable.
I unfortunately didn't recognize a certain quality the number has, and wound up reconstructing the quality by hand.
Hmm, now, the concept of introducing more operators...
on 12. April 2025, 23:57 by ibag
Very nice break-in!
on 7. April 2025, 16:29 by AMD
Phew, with this one I finally solved all the current Sudoku puzzles in the SVS series. I can't believe I finally caught up, haha.
I wasn't really a logic puzzle pro before starting this series, and I have to say it was really challenging for me! I can't express how much I've learned with all these variants and how impressed I am by the consistent quality of your puzzles.
Thank you, Richard, you are an extraordinary puzzle maker.
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Wow!
Thanks a lot for these kind words!
And congratulations on catching up. Well done!
on 7. April 2025, 13:45 by Piatato
Very nice! Surprisingly smooth once I got into it properly :)
on 6. April 2025, 16:14 by geronimo92
Really (too !) hard !!
on 6. April 2025, 11:41 by PixelPlucker
Great fun, thanks Richard! :)
on 4. April 2025, 15:01 by Ragna
Wow! Brilliant puzzle. Thank you. :-)
on 4. April 2025, 14:31 by mihel111
Beautiful puzzle. A bit mathy, but very interesting.
Well done.
