Digital Roots
(Published on 3. October 2021, 19:30 by Andrewsarchus)
Rules:
- Standard Sudoku rules apply.
-
Digital Root Arrows:
The bulb must contain the DIGITAL ROOT of the sum of the digits along the arrow. -
Digital Root Killer Cages:
The number in the upper left corner of the cage (if given) indicates the DIGITAL ROOT of the sum of the digits in the cage. -
Digital Root Little Killer Sums:
The digit sums of diagonals indicated by like-colored arrows outside of the grid MUST have the same digital root. The value corresponding to each color is left for the solver to discover, and they are not necessarily distinct.
(rules end here - explanation of digital root below)
To get the digital root of a number, sum its digits, and if the result is still more than one digit, repeat the process with the new number until a single digit result is reached.
Example: if an arrow (or cage) contains the the digits 4,7,8, then the sum is 19, and the digital root of that sum is obtained by first adding the digits of 19 to get 10, and then adding the digits of 10 to get 1. So the digit in the arrow bulb (or the cage number if given) would be a 1.
Play Online:
f-puzzles: Digital Roots
ctc: Digital Roots
Solution code: Row 7 and Column 7
(left to right, top to bottom, no spaces)
Comments
on 13. October 2025, 19:01 by Playmaker6174
Superb setting with a rather fun and surprisingly flowy solve throughout!
It took me a few minutes at first to have the right throught process and once doing so, the solve felt rather natural and there's always a clean way to articulate every logic here.
It certainly felt at 4 stars diff range but it wasn't brutal or anything, one just needs a crystal clear idea to work on the arithmetic works overall imo.
on 21. February 2025, 18:21 by valacd
Fantastic puzzle! It took me several attempts to solve, but every minute of it was fun. The digital roots constraint is very counter intuitive in the beginning, but got used to it and it offered such a vast space of possible combinations. Thank you so much for this puzzle!
on 4. August 2022, 02:31 by Andrewsarchus
added ctc link
on 28. October 2021, 18:03 by Chilly
Went astray in box 3, but got there in the end. Very nice puzzle - I would say 4* difficulty :)
on 4. October 2021, 19:41 by grkles
Wow! That was complex, but very satisfying.
on 3. October 2021, 19:32 by Andrewsarchus
formatting change
