Teaching article
A four-by-four sudoku answer needs a deduction behind it
Use the stated row, column and region constraints together.
A row may leave two possible symbols until a column or region supplies another constraint. Ask which alternative was excluded and why, making the reasoning visible instead of accepting a plausible-looking entry as settled.
Check all relevant constraints before entering a symbol. Explaining the exclusion of alternatives makes the reasoning visible to a partner.
Bring the constraints together
- Read all constraints.
- Find a constrained empty cell.
- Explain the deduction.
A row missing two symbols needs column evidence to choose between them.
A plausible guess is not a demonstrated deduction. Which constraint excludes the alternative?
Use symbols instead of digits.
Resources
- Puzzle Partner Challenge — Use the four-by-four puzzle to discuss deductions from the stated constraints.
Further reading
Read next
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- A treasure clue should work for someone who did not write it
- A cooperative puzzle needs a reason to share information
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