About Calcudoku #839
Calcudoku #839 was the puzzle for Monday, October 19, 2026, a medium one: a 5 × 5 grid in 9 cages. Everyone who played Calcudoku that day got the same puzzle, and it stays here to play for 60 days.
New to Calcudoku? The rules, tips and common questions are on the Calcudoku page, and How to Solve Calcudoku Puzzles goes into strategy.
Other days of Calcudoku
- Calcudoku #842, Oct 22
- Calcudoku #841, Oct 21
- Calcudoku #840, Oct 20
- Calcudoku #838, Oct 18
- Calcudoku #837, Oct 17
- Calcudoku #836, Oct 16
- Today’s puzzle, #851
Every day of the last 60 is in the puzzle archive.