This is a free “warm-up” puzzle; Season 4 subscribers will see today’s main puzzle in the same style posted at 9:05 AM PT.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: Two and One

Author/Opus: This is the 512nd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Place the numbers in the indicated range (1-6 in the puzzle, 1-5 in the example) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell. A ? can represent any sum of 1 or larger.

Difficulty: 1.5 stars

Time Standards (highlight to view): Grandmaster = 1:15, Master = 1:30, Expert = 3:00

Solution: PDF and solving animation.

Note: Follow this link for other Japanese Sums puzzles.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 6 Discussion post on the GMPuzzles Discord.

This is a free “warm-up” puzzle; Season 4 subscribers will see today’s main puzzle in the same style posted at 9:05 AM PT.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: Triangular Numbers

Author/Opus: This is the 127th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Fill some cells with numbers 1-4 so that each row and column contains each number from 1 to 4 exactly once as well as one empty cell. Numbers outside of the grid indicate the sum of all numbers in the first connected group in that direction as in a Japanese Sums puzzle.

See also this example with the numbesr 1 to 4 and two empty cells:

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:30, Master = 0:45, Expert = 1:30

Solution: PDF and solving animation.

Note: Follow this link for other Japanese Sums puzzles. Also, visit this page to purchase all of the puzzles from the 30th World Puzzle Championship including some Easy as Japanese Sums.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Week 6 Discussion post on the GMPuzzles Discord.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: Almost All Triples

Author/Opus: This is the 19th puzzle from guest contributor Salih Alan.

Rules: Fill some cells with numbers 1-5 so that each row and column contains each number from 1 to 5 exactly once as well as three empty cells (1-4 and two empty cells in the example). Numbers outside of the grid indicate the sum of all numbers in the first connected group in that direction as in a Japanese Sums puzzle.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 8:30, Master = 17:15, Expert = 34:30

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

Since 2021, we have posted some extra difficult Sunday Stumpers, about once a month. These will be quite tough puzzles, but with a logical path to be found (and solution videos to help). This seventh Sunday Stumper of 2022 is a variation of Japanese Sums by John Bulten.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: Yamato

Author/Opus: This is the 88th puzzle from our contributing puzzlemaster John Bulten.

Rules: Standard Japanese Sums rules: Place the numbers in the indicated range (1-9) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell. A ? can represent any sum of 1 or larger.

Also, all unused cells must form an unknown fleet of 1-cell wide ships in the grid. Each segment of a ship occupies a single cell, and ships do not touch each other, even diagonally.

Difficulty: 5 stars

Time Standards (highlight to view): Grandmaster = 18:30, Master = 30:00, Expert = 1:00:00

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: Why was 6 Afraid of 7?

Author/Opus: This is the 10th puzzle from guest contributor Sam Cappleman-Lynes.

Rules: Place the numbers in the indicated range (1-8) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell. A ? can represent any sum of 1 or larger.

Difficulty: 4.5 stars

Time Standards (highlight to view): Grandmaster = 12:00, Master = 20:00, Expert = 40:00

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: Twenty20 Vision

Author/Opus: This is the 238th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: Place the numbers in the indicated range (1-9) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell. The adjacent question marks (??) show two-digit numbers, not two groups)

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 6:00, Master = 9:15, Expert = 18:30

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: Doubles

Author/Opus: This is the 96th puzzle from our contributing puzzlemaster Ashish Kumar.

Rules: Place the numbers in the indicated range (1-6) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell.

Difficulty: 3.5 stars

Time Standards (highlight to view): Grandmaster = 4:30, Master = 8:15, Expert = 16:30

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: Common Denominations

Author/Opus: This is the 415th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Place the numbers in the indicated range (1-6) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:30, Master = 4:00, Expert = 8:00

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: 1 to 10

Author/Opus: This is the 372nd puzzle from our managing editor Serkan Yürekli.

Rules: Fill some cells with numbers 1-4 so that each row and column contains each number from 1 to 4 exactly once as well as two empty cells. Numbers outside of the grid indicate the sum of all numbers in the first connected group in that direction as in a Japanese Sums puzzle.

Difficulty: 2.5 stars

Time Standards (highlight to view): Grandmaster = 2:00, Master = 3:15, Expert = 6:30

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between number entry and shading modes.)

Theme: High Five

Author/Opus: This is the 50th puzzle from our contributing puzzlemaster JinHoo Ahn.

Rules: Place the numbers in the indicated range (1-5) in some of the cells so that no number is repeated in any row or column. Numbers on the outside of the grid indicate the sums of adjacent number groups in that row or column, in order. Each sum is separated by at least one unused cell. A ? can represent any sum of 1 or larger.

Difficulty: 1 star

Time Standards (highlight to view): Grandmaster = 0:40, Master = 1:00, Expert = 2:00

Solution: PDF and solving video.

Note: Follow this link for other Japanese Sums puzzles.