Full House
Full House is the most basic and simple technique in Number Place (Sudoku). When only one empty cell remains in a row, column, or block, the number that goes there is automatically determined. This is the first technique beginners should learn.
How to Use Full House
Scan the entire board for rows, columns, or blocks with only one empty cell.
Check which numbers are already placed in that row, column, or block.
The missing number from 1–9 is your answer.
Example
For instance, if a row contains ‘1, 2, 3, 4, 5, 6, 7, 9’ with one empty cell, that cell must be ‘8.’ Simply find the one number missing from 1–9 — it’s that easy.
Tips for Finding Full House
When starting a puzzle, check rows, columns, and blocks with the most numbers filled first. Cells that can be filled via Full House often create hints for surrounding areas. Full House frequently occurs as a result of filling numbers with other techniques, so develop the habit of checking nearby rows, columns, and blocks immediately after placing a number.