Platon Sudoku · Sudoku Study
Candidates · Core Concepts
A candidate is a digit that may still fit in an empty cell. It is a possibility, not a placed answer.
This course is adapted from Platon Sudoku App. Read the complete example here, then continue learning and practising in the app.
View on Google PlayDefinition
A candidate is a digit that may still fit in an empty cell. It is a possibility, not a placed answer.
How to find it
Check that the cell is empty, then rule out digits already placed in its row, column and box.
Common mistake
A small note is a candidate; a large placed digit is not. The local diagram shows only relevant notes.
Worked example
Teaching board · local candidate diagram
Observe candidates
A candidate is a digit that may still fit in an empty cell. It is a possibility, not a placed answer.
Verify the condition
Check that the cell is empty, then rule out digits already placed in its row, column and box.
Draw the conclusion
The highlighted cell is empty, and its small 2 is still a possible value.
Recognition practice
Teaching board · local candidate diagram
Recognition practice 1
Is the highlighted small digit still a candidate?
Draw the conclusion
Yes
Recognition practice 2
Is the highlighted small digit still a candidate?
Draw the conclusion
No
Recognition practice 3
Is the highlighted small digit still a candidate?
Draw the conclusion
Yes
Recognition practice 4
Is the highlighted small digit still a candidate?
Draw the conclusion
No
Recognition practice 5
Is the highlighted small digit still a candidate?
Draw the conclusion
Yes
Recognition practice 6
Is the highlighted small digit still a candidate?
Draw the conclusion
No
Recognition practice 7
Is the highlighted small digit still a candidate?
Draw the conclusion
Yes
Recognition practice 8
Is the highlighted small digit still a candidate?
Draw the conclusion
No
Recognition practice 9
Is the highlighted small digit still a candidate?
Draw the conclusion
Yes
Recognition practice 10
Is the highlighted small digit still a candidate?
Draw the conclusion
No
Recognition practice 11
Is the highlighted small digit still a candidate?
Draw the conclusion
Yes
Recognition practice 12
Is the highlighted small digit still a candidate?
Draw the conclusion
No
Practice
This course is adapted from Platon Sudoku App. Read the complete example here, then continue learning and practising in the app.
View on Google Play