The Tenth Box: Arrows
(Published on 25. June 2026, 15:40 by Liamhere)
Rules:
Normal Sudoku: Fill the grid with digits 1–9 such that every row, column, and 3 by 3 box contains each digit exactly once.
The Tenth Box: The nine center cells of the standard 3 by 3 boxes form a "Tenth Box" which must also contain the digits 1–9 without repetition.
Any rule or constraint in a standard 3 by 3 box is applied to the corresponding cells in the Tenth Box. Constraints map from the nine standard boxes to the Tenth Box, but not vice-versa.
Killer Cages: Digits in a cage must sum to the value in the top-left corner. Digits cannot repeat within a cage.
Arrows: The sum of the digits along an arrow must equal the digit in the attached circle.
Example: In this puzzle, the first and second cells in Box 9 are inside the cage of sum 9. This means that the sum of the digits in cells R7C7 and R7C8 is 9. Furthermore, the sum of the digits in the first and second cells of the Tenth Box (R2C2 and R2C5) is also 9.
Example: In this puzzle, the arrow in Box 9 indicates that the fourth and eighth cell in Box 9 sums to the sixth cell of Box 9 (R8C7+R9C8=R8C9). Furthermore, the fourth and eighth cell of the Tenth Box must also sum to the sixth cell of the Tenth Box (R5C2+R8C5=R5C8).
Tenth Box Puzzles:
Solution code: Column 3 (top to bottom)
