Lesson 2 · Read the board
Rows, Columns and Boxes
See how every cell belongs to three connected groups at the same time.
See the logic move
Use Next to reveal each reason. On the final step, tap the highlighted cell to complete the move yourself.
Step 1 of 3
One row
The blue band is the selected cell's row.
Ask about any cellTap a square on the board
Select an empty cell to see its legal candidates and why the other digits are blocked.
Why this works
- 1
Focus: Start here. This is the cell or area being investigated. R5C5.
- 2
Relevant cells: These cells share the row, column, or box used by this step. Row 5.
What the board is showing
FocusStart here. This is the cell or area being investigated.R5C5
Relevant cellsThese cells share the row, column, or box used by this step.Row 5
Explain it simply
A cell has three neighbourhoods: its horizontal row, vertical column, and small box.
Step by step
- Find the cell's row.
- Trace its column.
- Locate its 3x3 box.
- Combine the information from all three.
Quick check: How many rows, columns, and boxes does one cell belong to?
One row, one column, and one 3x3 box.
Turn logic into skill