The Twelve Days of Sudoku #4 by Thomas Snyder
or solve online (using our beta test of Penpa-Edit tools)
Author/Opus: This is the 538th puzzle from Thomas Snyder, aka Dr. Sudoku.
Rules: Standard Sudoku rules.
Time Standards (highlight to view): Grandmaster = 3:30, Master = 6:30, Expert = 13:00
Solution: PDF and solving animation.
Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More Sudoku including variations can be found in these books in our e-store. Also, visit this page to purchase all of the puzzles from the 16th World Sudoku Championship including classic Sudoku.
Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our The Twelve Days of Sudoku Discussion post on the GMPuzzles Discord.
Note 3: Please check lesson notes from Dr. Sudoku on Google Docs.