Easy Sandwich Sudoku

Clues outside the grid give the sum of digits sandwiched between the 1 and the 9 in each row and column.

Easy Medium Hard Expert

New to Sandwich Sudoku? Each outside number is the sum of digits between the 1 and 9 in that row or column. Start with zero-sum clues.

20
12
16
5
22
12
7
5
35
33
23
8
0
3
0
13
7
0
2
3
4
7
1
6
2
5
4
6
8
3
1
6
5
7
8
5
9
3
2
4
5
1
9
3
6
1
3
4
1
7
9
3
8
7
1
9
Mistakes
0/3
Score
-
Time
00:00
Try Medium Sandwich Sudoku →
Progress0%

What is Sandwich Sudoku?

Difficulty
★★★★☆
4/5
Constraint Type
Outside Clues
Typical Givens
4–10 clue values
Avg. Solve (Easy)
12 min

Solving Techniques for Easy Level

Technique Description Level
Clue 0 Means Adjacent 1 and 9 A sandwich clue of 0 means 1 and 9 are side-by-side with nothing between them. Place this pair immediately. Beginner
Clue 35 Means 1 and 9 at Ends A clue of 35 = 2+3+4+5+6+7+8. All middle digits are sandwiched, placing 1 and 9 at the two ends of the row/column. Beginner

Ready to go deeper? Try Medium Sandwich Sudoku to unlock Intermediate techniques.

Techniques to Master at Easy

  • Notes in Sudoku — Before placing anything, note where 1 and 9 can legally sit in each row and column given its clue — sandwich solving is crust bookkeeping, and notes are the ledger.
  • Last Possible Number technique — A clue of 0 glues 1 and 9 together and a clue of 35 pins them to the ends — either way, whole rows of candidates vanish and several cells drop to one digit.
  • Last Remaining Cell technique — Once a row's 1 is placed, the column clues immediately restrict where that column's 9 can sit — chase each crust digit to its last legal cell.

Average Solve Time by Difficulty

Easy
12 min
Medium
26 min
Hard
52 min
Expert
85 min
Want a full walkthrough of rules, strategies, and solving steps? How to Play Sandwich Sudoku →

Related Variants

Killer Sudoku

Both are sum-deduction puzzles at heart — killer's 45 rule and sandwich's crust sums exercise the same arithmetic.

Skyscraper Sudoku

Outside clues again, but read as building visibility instead of sums — the same edge-of-grid deduction style.

Outside Sudoku

The gentlest outside-clue cousin: border digits simply belong in the nearest three cells, no arithmetic required.

Frequently Asked Questions — Easy Sandwich Sudoku

What is Sandwich Sudoku?
Sandwich Sudoku is a Sudoku variant where numbers appear outside the grid along each row and column. Each outside number gives the sum of all digits sandwiched between the 1 and the 9 in that row or column. Standard Sudoku rules apply: every row, column, and 3x3 box must contain digits 1 through 9 exactly once.
What does 'sandwiched between 1 and 9' mean?
In each row and column, the digit 1 and the digit 9 each appear exactly once. The sandwich sum counts all digits that sit between those two positions. If 1 is in column 3 and 9 is in column 7, then the digits in columns 4, 5, and 6 are sandwiched — their sum equals the outside clue.
What does a sandwich clue of 0 mean?
A clue of 0 means there are no digits between the 1 and the 9 — they must be in adjacent cells. This is one of the most powerful clues because it restricts the positions of both 1 and 9 very sharply.
How do I start solving easy Sandwich Sudoku?
Start with the most extreme sandwich sums: clues of 0 (1 and 9 are adjacent), 35 (all seven middle digits are between them, meaning 1 and 9 are at the ends), or small values like 2 or 3 that have very few possible digit combinations. These anchor the 1 and 9 positions first.
How is Sandwich Sudoku different from Killer Sudoku?
Killer Sudoku uses cage-shaped groups where digits cannot repeat and sum to a given value. Sandwich Sudoku uses outside clues that describe the sum of digits between the 1 and 9 in each row and column — the 1 and 9 are not sandwiched themselves and act as boundaries rather than contributors.

More questions? See the full Sandwich Sudoku guide.