100 Large Print Easy 6x6 Sudoku Puzzles for Adults: Only One ... - Free Printable

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

In a 6x6 Sudoku:
- The grid is divided into six 2x3 boxes (two rows high, three columns wide).
- Each row must contain the numbers 1 to 6 exactly once.
- Each column must contain the numbers 1 to 6 exactly once.
- Each 2x3 box must contain the numbers 1 to 6 exactly once.

Here’s the starting grid:

Row 1: _ _ _ | 6 _ _
Row 2: 4 6 _ | _ 5 3
Row 3: 1 2 3 | _ _ _
Row 4: _ _ _ | _ 3 1
Row 5: 2 5 _ | _ 1 4
Row 6: 3 1 4 | 5 _ 6

We’ll fill in missing numbers logically.

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Start with Row 6: [3, 1, 4, 5, ?, 6] → Missing number is 2. So Row 6, Column 5 = 2.

Now Row 6 is complete: 3 1 4 5 2 6

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Look at Column 5 (from top to bottom):

Row 1: ?
Row 2: 5
Row 3: ?
Row 4: 3
Row 5: 1
Row 6: 2 ← just filled

So Column 5 has: ?, 5, ?, 3, 1, 2 → Missing numbers are 4 and 6.

Check Row 1, Column 5: What can go there? Look at Row 1: already has 6 in column 4. So 6 cannot be in Row 1 again. Therefore, Row 1, Col 5 must be 4. Then Row 3, Col 5 must be 6.

Update:

Row 1, Col 5 = 4
Row 3, Col 5 = 6

Now Column 5 is: 4, 5, 6, 3, 1, 2 → Complete!

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Now look at Row 1: [_ _ _ 6 4 _]

Missing numbers: 1, 2, 3, 5 — but wait, we have 6 and 4 already. So need 1,2,3,5 for the four blanks? Wait — no, Row 1 has 6 cells total. We have two filled: col4=6, col5=4 → so 4 empty cells left. Need to place 1,2,3,5.

But let’s check Box 1 (top-left 2x3 box: Rows 1–2, Cols 1–3)

Current Box 1:

Row 1: ? ? ?
Row 2: 4 6 ?

Already has 4 and 6. So missing: 1,2,3,5

Also, Row 2: [4,6,?, ?,5,3] → so Row 2, Col 3 must be one of 1 or 2 (since 3,4,5,6 are used in row). But also must fit in Box 1.

Wait — better to look at Row 2 first.

Row 2: [4,6,?, ?,5,3] → missing numbers: 1 and 2.

So Col 3 and Col 4 in Row 2 must be 1 and 2.

Now check Column 3:

Row 1: ?
Row 2: ? (must be 1 or 2)
Row 3: 3
Row 4: ?
Row 5: ?
Row 6: 4

So Column 3 already has 3 and 4. So Row 2, Col 3 cannot be 3 or 4 — which it isn’t, since only 1 or 2 allowed.

Now check Box 1 again: Rows 1–2, Cols 1–3.

Cells:

(1,1) (1,2) (1,3)
(2,1)=4 (2,2)=6 (2,3)=?

Must contain 1,2,3,5 besides 4,6.

Row 3, Col 3 is 3 — that’s in Box 3 (Rows 3–4, Cols 1–3), not Box 1. So 3 is still available for Box 1.

Actually, let’s list what’s in Box 1 so far: only 4 and 6. So needs 1,2,3,5.

Now Row 2, Col 3 must be 1 or 2 (from row constraint).

Try putting 1 in Row 2, Col 3.

Then Row 2, Col 4 must be 2 (since row needs 1 and 2).

Check if that works.

Row 2 becomes: 4 6 1 | 2 5 3 → looks good.

Now Box 1: Row 1 cols 1-3 + Row 2 cols 1-3 = [?,?,?] and [4,6,1] → so Box 1 now has 1,4,6 → needs 2,3,5.

Row 1 cols 1-3 must be 2,3,5 in some order.

Now look at Column 1:

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

So Column 1 has: ?,4,1,?,2,3 → missing 5 and 6.

But Row 1, Col 1 must be from {2,3,5} (from Box 1 needs) — but 2 and 3 are already in Column 1 (rows 5 and 6). So Row 1, Col 1 cannot be 2 or 3 → must be 5.

Set Row 1, Col 1 = 5.

Now Box 1: Row 1 cols 1-3: 5, ?, ? → and Row 2: 4,6,1 → so Box 1 has 1,4,5,6 → needs 2 and 3.

So Row 1, Col 2 and Col 3 must be 2 and 3.

Now Column 2:

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

So Column 2 has: ?,6,2,?,5,1 → missing 3 and 4.

Row 1, Col 2 must be 2 or 3 (from above) — but 2 is already in Column 2 (Row 3), so cannot be 2 → must be 3.

Set Row 1, Col 2 = 3.

Then Row 1, Col 3 must be 2 (only one left for Box 1).

Now Row 1: [5,3,2,6,4,?] → last cell (Col 6) must be 1 (only number missing in row).

Set Row 1, Col 6 = 1.

Now Row 1 is complete: 5 3 2 6 4 1

Check Column 6:

Row 1: 1
Row 2: 3
Row 3: ?
Row 4: 1 → wait! Row 4, Col 6 is 1 (given), and Row 1, Col 6 is 1 → conflict! Oh no!

Mistake here.

Row 4, Col 6 is given as 1. And I just put Row 1, Col 6 = 1 → same column → invalid.

Where did I go wrong?

Backtrack.

When I set Row 2, Col 3 = 1, then Row 2, Col 4 = 2.

But maybe that’s wrong. Let me try the other option.

Earlier, Row 2: [4,6,?, ?,5,3] → missing 1 and 2 for cols 3 and 4.

I tried Col3=1, Col4=2 → led to conflict.

Now try Col3=2, Col4=1.

So Row 2: 4 6 2 | 1 5 3

Now Box 1: Row 1 cols 1-3 + Row 2 cols 1-3 = [?,?,?] and [4,6,2] → so has 2,4,6 → needs 1,3,5.

Column 1: as before, has 4,1,2,3 → missing 5,6.

Row 1, Col 1 must be from {1,3,5} (Box 1 needs) — but Column 1 already has 1,2,3,4 → so only possible is 5 or 6. But 6 not in Box 1 options? Box 1 needs 1,3,5 — so Row 1, Col 1 must be 5 (since 1 and 3 are in Column 1 already).

Set Row 1, Col 1 = 5.

Box 1 now: 5,?,? and 4,6,2 → has 2,4,5,6 → needs 1,3.

So Row 1, Col 2 and 3 must be 1 and 3.

Column 2: has 6,2,5,1 → missing 3,4.

Row 1, Col 2 must be 1 or 3 — but 1 is in Column 2 (Row 6), so cannot be 1 → must be 3.

Set Row 1, Col 2 = 3.

Then Row 1, Col 3 = 1.

Now Row 1: [5,3,1,6,4,?] → missing 2.

Set Row 1, Col 6 = 2.

Check Column 6: Row 1=2, Row 2=3, Row 4=1, Row 5=4, Row 6=6 → so far 2,3,1,4,6 → missing 5. So Row 3, Col 6 must be 5.

Set Row 3, Col 6 = 5.

Now Row 3: [1,2,3, ?,6,5] → missing 4.

So Row 3, Col 4 = 4.

Set Row 3, Col 4 = 4.

Now Row 3 complete: 1 2 3 4 6 5

Check Box 3 (Rows 3–4, Cols 1–3): Row 3: 1,2,3; Row 4: ?,?,? → so far 1,2,3 → needs 4,5,6.

Column 1: Row 1=5, Row 2=4, Row 3=1, Row 4=?, Row 5=2, Row 6=3 → has 5,4,1,2,3 → missing 6. So Row 4, Col 1 = 6.

Set Row 4, Col 1 = 6.

Column 2: Row 1=3, Row 2=6, Row 3=2, Row 4=?, Row 5=5, Row 6=1 → has 3,6,2,5,1 → missing 4. So Row 4, Col 2 = 4.

Set Row 4, Col 2 = 4.

Column 3: Row 1=1, Row 2=2, Row 3=3, Row 4=?, Row 5=?, Row 6=4 → has 1,2,3,4 → missing 5,6.

Row 4, Col 3 must be from Box 3 needs: Box 3 has Row 3:1,2,3; Row 4:6,4,? → so far 1,2,3,4,6 → needs 5. So Row 4, Col 3 = 5.

Set Row 4, Col 3 = 5.

Now Row 4: [6,4,5, ?,3,1] → missing 2.

So Row 4, Col 4 = 2.

Set Row 4, Col 4 = 2.

Now Row 4 complete: 6 4 5 2 3 1

Check Box 4 (Rows 3–4, Cols 4–6): Row 3:4,6,5; Row 4:2,3,1 → all numbers 1-6 present? 4,6,5,2,3,1 → yes.

Now Row 5: [2,5,?, ?,1,4] → missing 3 and 6.

Column 3: has 1,2,3,5,4 → missing 6. So Row 5, Col 3 = 6.

Set Row 5, Col 3 = 6.

Then Row 5, Col 4 = 3 (only one left).

Set Row 5, Col 4 = 3.

Row 5 complete: 2 5 6 3 1 4

Now check Column 4:

Row 1:6, Row 2:1, Row 3:4, Row 4:2, Row 5:3, Row 6:5 → 6,1,4,2,3,5 → all good.

Column 3: Row1:1, R2:2, R3:3, R4:5, R5:6, R6:4 → 1,2,3,5,6,4 → good.

All rows and columns should be checked, but let's write the full grid.

Final Grid:

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

Verify each row has 1-6:

R1: 5,3,1,6,4,2 → yes
R2: 4,6,2,1,5,3 → yes
R3: 1,2,3,4,6,5 → yes
R4: 6,4,5,2,3,1 → yes
R5: 2,5,6,3,1,4 → yes
R6: 3,1,4,5,2,6 → yes

Columns:

C1: 5,4,1,6,2,3 → yes
C2: 3,6,2,4,5,1 → yes
C3: 1,2,3,5,6,4 → yes
C4: 6,1,4,2,3,5 → yes
C5: 4,5,6,3,1,2 → yes
C6: 2,3,5,1,4,6 → yes

Boxes:

Box1 (R1-2,C1-3): 5,3,1 / 4,6,2 → 1,2,3,4,5,6 → yes
Box2 (R1-2,C4-6): 6,4,2 / 1,5,3 → 1,2,3,4,5,6 → yes
Box3 (R3-4,C1-3): 1,2,3 / 6,4,5 → yes
Box4 (R3-4,C4-6): 4,6,5 / 2,3,1 → yes
Box5 (R5-6,C1-3): 2,5,6 / 3,1,4 → yes
Box6 (R5-6,C4-6): 3,1,4 / 5,2,6 → yes

Perfect.

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