Platon Sudoku · Sudoku Study

Which Cell to Fill Next · Sudoku

Not sure where to look? Try a digit that already appears often. Here we choose 8 and look for boxes still missing it.

This course is adapted from Platon Sudoku App. Read the complete example here, then continue learning and practising in the app.

Start with one digit

Not sure where to look? Try a digit that already appears often. Here we choose 8 and look for boxes still missing it.

This box needs a 8. The marked digits rule out the crossed cells: a row or column cannot repeat 8.

The box must contain a 8. After ruling out the other positions, only the highlighted cell remains.

Look at another box missing 8. The existing 8s rule out positions until only one place remains here too.

Scan the boxes for the same digit. If you find no clear move, try another digit. Fill a cell when you can explain why.

This course is adapted from Platon Sudoku App. Read the complete example here, then continue learning and practising in the app.