Scan each row, column, and 3×3 box for missing numbers
Fill in any cell that has only one possible number
Use elimination to remove impossible candidates from each empty cell
Check for hidden singles in rows, columns, and boxes
Repeat scanning after every placement
Look for pairs, triples, and other candidate patterns
Use box-line interactions to narrow possibilities
Continue applying logical deductions until the puzzle is complete
If needed, test a candidate and backtrack carefully
Verify that each row, column, and box contains digits 1 through 9 exactly once