3 Sudoku Puzzle Books Sudoku Printable Printable Sudoku Puzzle 6x6 ... - Free Printable

Let’s solve this 6x6 Sudoku puzzle step by step.

In a 6x6 Sudoku:
- The grid is divided into 6 rows and 6 columns.
- It’s also split into 6 smaller boxes (each 2 rows x 3 columns).
- Each row must have the numbers 1 to 6, no repeats.
- Each column must have the numbers 1 to 6, no repeats.
- Each small box must have the numbers 1 to 6, no repeats.

We’ll fill in the empty cells one by one, using logic.

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Start with Row 1: [5, 1, _, _, 2, 3]
Missing numbers: 4, 6
Look at columns for clues.

Cell (1,3) — column 3 has: _, _, 3, _, 5, _ → so far 3,5 → can’t be 4 or 6? Wait, let’s check box.

Box 1 (top-left 2x3):
Rows 1-2, Columns 1-3:
5 1 _
3 2 _
So missing in box: 4,6
Row 1 needs 4,6 in columns 3 and 4.
Column 3: already has 3 (row3), 5 (row5) → so 4 or 6 ok.
Column 4: currently empty in row1, but row4 col4 is 6 → so column 4 already has 6 → so cell (1,4) cannot be 6 → must be 4.
Then cell (1,3) must be 6.

→ Row 1: 5, 1, 6, 4, 2, 3

Now Row 2: [3, 2, _, _, 5, _]
Missing: 1,4,6
Box 1 (rows1-2, cols1-3) now has:
5 1 6
3 2 _ → missing 4 → so cell (2,3) = 4

Now Row 2: 3, 2, 4, _, 5, _ → missing 1,6
Column 4: we just put 4 in row1, and row4 col4 is 6 → so column 4 has 4,6 → so cell (2,4) cannot be 6 → must be 1
Then cell (2,6) = 6

→ Row 2: 3, 2, 4, 1, 5, 6

Now Row 3: [6, 5, 3, _, 1, 4] → only missing one number: 2 → so cell (3,4) = 2

→ Row 3: 6, 5, 3, 2, 1, 4

Now Row 4: [_, _, _, 6, 3, _]
Missing: 1,2,4,5
But look at box 4 (middle-left: rows3-4, cols1-3):
Row3: 6,5,3
Row4: _,_,_ → so far 3,5,6 → missing 1,2,4
Also, column 1: has 5,3,6,_,1,_ → so far 1,3,5,6 → missing 2,4
Column 2: has 1,2,5,_,_,3 → so far 1,2,3,5 → missing 4,6
Column 3: has 6,4,3,_,5,_ → so far 3,4,5,6 → missing 1,2

Try cell (4,1): column 1 missing 2,4; box 4 missing 1,2,4 → possible 2 or 4
But row 4 already has 6,3 → so 2 and 4 are still possible.

Wait — look at column 1:
Row1:5, Row2:3, Row3:6, Row4:?, Row5:1, Row6:? → so values present: 1,3,5,6 → missing 2,4
Row5 col1 is 1 → so row4 col1 can't be 1 → ok.

Now look at box 4 again:
Cells:
(3,1)=6, (3,2)=5, (3,3)=3
(4,1)=?, (4,2)=?, (4,3)=?
Must contain 1,2,4

Column 2: has 1,2,5,?, ?,3 → so row4 col2 cannot be 1,2,3,5 → must be 4 or 6 → but 6 already in box → so must be 4?
Wait — column 2: row1:1, row2:2, row3:5, row4:?, row5:?, row6:3 → so used: 1,2,3,5 → missing 4,6
But box 4 already has 6 (from row3 col1) → so cell (4,2) cannot be 6 → must be 4

→ So (4,2) = 4

Now box 4: missing 1,2 → cells (4,1) and (4,3)

Column 1: missing 2,4 → but 4 is now used in (4,2) → so (4,1) must be 2 (since 4 is taken in row4? Wait no — row4 can have multiple numbers, but column 1 needs 2 or 4. But (4,2) is 4 — that’s column 2, not column 1. So column 1 still needs 2 and 4.

But in box 4, we need 1 and 2 for (4,1) and (4,3). Column 1 can take 2 or 4 — but 4 is not in the missing for box 4? Box 4 missing 1,2 → so (4,1) must be 1 or 2.

Column 1: missing 2,4 → so (4,1) must be 2 (since 4 not in box 4 missing list? Wait, contradiction?)

Wait — let's list box 4 again:

Box 4 (rows 3-4, cols 1-3):

Row3: 6,5,3
Row4: ?,4,? → because we set (4,2)=4

So current numbers in box: 3,4,5,6 → missing 1,2

So (4,1) and (4,3) must be 1 and 2.

Column 1: has 5,3,6,?,1,? → so far 1,3,5,6 → missing 2,4 → so (4,1) must be 2 (because 4 is not available in box 4 missing? But 4 is already placed in (4,2), which is same row but different column — that’s fine. But for column 1, (4,1) must be 2 or 4. But in box 4, (4,1) must be 1 or 2. So intersection: must be 2.

→ (4,1) = 2

Then (4,3) = 1

Now Row 4: 2, 4, 1, 6, 3, ? → missing 5 → so (4,6) = 5

→ Row 4: 2, 4, 1, 6, 3, 5

Now Row 5: [1, _, 5, _, 4, _]
Missing: 2,3,6
Box 5 (middle-right: rows3-4, cols4-6):
Row3: 2,1,4
Row4: 6,3,5 → so box 5 has 1,2,3,4,5,6 → complete! Good.

Now Row 5: 1, ?, 5, ?, 4, ?
Columns:
Col2: has 1,2,5,4,?,3 → so far 1,2,3,4,5 → missing 6 → so (5,2) = 6

Then Row 5: 1,6,5,?,4,? → missing 2,3

Col4: has 4,1,2,6,?,5 → so far 1,2,4,5,6 → missing 3 → so (5,4) = 3

Then (5,6) = 2

→ Row 5: 1, 6, 5, 3, 4, 2

Now Row 6: [_, 3, _, 5, _, 1]
Missing: 2,4,6
Col1: has 5,3,6,2,1,? → so far 1,2,3,5,6 → missing 4 → so (6,1) = 4

Then Row 6: 4,3,?,5,?,1 → missing 2,6

Col3: has 6,4,3,1,5,? → so far 1,3,4,5,6 → missing 2 → so (6,3) = 2

Then (6,5) = 6

→ Row 6: 4, 3, 2, 5, 6, 1

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Now let’s write the full grid:

Row 1: 5, 1, 6, 4, 2, 3
Row 2: 3, 2, 4, 1, 5, 6
Row 3: 6, 5, 3, 2, 1, 4
Row 4: 2, 4, 1, 6, 3, 5
Row 5: 1, 6, 5, 3, 4, 2
Row 6: 4, 3, 2, 5, 6, 1

Check all rows, columns, and boxes.

Rows: all have 1-6, no repeats.

Columns:

Col1: 5,3,6,2,1,4 → good
Col2: 1,2,5,4,6,3 → good
Col3: 6,4,3,1,5,2 → good
Col4: 4,1,2,6,3,5 → good
Col5: 2,5,1,3,4,6 → good
Col6: 3,6,4,5,2,1 → good

Boxes:

Box1 (R1-2,C1-3):
5,1,6
3,2,4 → 1-6 good

Box2 (R1-2,C4-6):
4,2,3
1,5,6 → good

Box3 (R3-4,C1-3):
6,5,3
2,4,1 → good

Box4 (R3-4,C4-6):
2,1,4
6,3,5 → good

Box5 (R5-6,C1-3):
1,6,5
4,3,2 → good

Box6 (R5-6,C4-6):
3,4,2
5,6,1 → good

All checks pass.

Final Answer:
5 1 6 4 2 3
3 2 4 1 5 6
6 5 3 2 1 4
2 4 1 6 3 5
1 6 5 3 4 2
4 3 2 5 6 1