Sandwich Sudoku

Rules

A number beside a row tells you the total of the digits sitting strictly between the 1 and the 9 in that row. A clue of 0 means the 1 and the 9 are neighbours; a clue of 35 means every other digit is between them.

• Each outside number is the sum of the cells between 1 and 9 in that row or column.
• The 1 and the 9 themselves are never counted.
• A clue of 0 forces 1 and 9 to touch, in either order.
• The maximum clue is 35 — 2+3+4+5+6+7+8 — which means all of them sit between.
• Clues are given on the left of each row and above each column.

Good to know

Ordinary sudoku rules still apply underneath the variant: every row, column and 3×3 box holds 1–9 exactly once. The extra rule sits on top and is usually what breaks the puzzle open.

More sudoku

All sudoku variants ↗

Or read how to play Sudoku ↗.