Sudoku rules check
A quick Sudoku rules check: complete a row and answer a question about the rules. Pass it to unlock the solving techniques. Rules check · lesson 1 of 1.
The lesson in words
Two questions. First, a cell to fill.
Try it: Row 2 has one cell left. Fill it.
Rules done. Now for the techniques that solve real puzzles.
Questions
Which of these must contain every digit from 1 to 9?
All three: rows, columns and boxes.