Sudoku for beginners: a practical first solve
Learn Sudoku rows, columns, boxes, candidate elimination, naked singles, and hidden singles with simple examples before playing a daily puzzle.
Know the three constraints
A standard Sudoku has nine rows, nine columns, and nine 3 × 3 boxes. Each must contain the digits 1 through 9 exactly once. The printed numbers are fixed. You do not add, subtract, or calculate totals; the puzzle is about eliminating placements that break those constraints.
Start where information is strongest
Look for a row, column, or box with many numbers already filled. List what is missing. Then inspect each empty square’s other row, column, and box to rule out impossible choices. Working on the fullest region first usually gives you fewer possibilities to track.
Find a naked single
Imagine a square’s row allows only 2, 5, or 8. Its column already contains 2, and its box already contains 8. Only 5 remains, so you can place 5. This is a naked single: one possible value for one square after all three constraints are considered.
Look for a hidden single
Now imagine a box has several empty squares, and only one of them can contain 7. Even if that square appears to allow other digits, it must be 7 because the box needs a 7 somewhere. This is a hidden single: one possible square for a particular digit within a region.
Recheck after every placement
Each number can remove candidates from its row, column, and box. Scan those regions again before jumping elsewhere. If you get stuck, work on another region and return. If you notice a contradiction, revisit your most recent uncertain placement rather than stacking guesses on top of it.
Try the daily board
In Borough, select a square and type a number or tap the number pad. Erase changes your own entries; fixed clues cannot be edited. Your entries appear immediately and save in the background. When the grid is filled, choose Check puzzle. A successful solve earns 100 points.