PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a composite mode for line/edge drawing and a number entry mode.)

Theme: Primes (for Daniel Cohen)

Author/Opus: This is the 26th puzzle from our contributing puzzlemaster Carl Worth.

Rules: Standard Fillomino rules, except that the size of all regions must be a prime number (2, 3, 5, 7, …).

Answer String: For each cell in the marked columns, enter the area of the polyomino it belongs to. Enter just the last digit for any two-digit number. Start with the 4th column, followed by a comma, followed by the 8th column.

Time Standards (highlight to view): Grandmaster = 4:15, Master = 8:00, Expert = 16:00

Solution: PDF

Note: Follow this link for other classic Fillomino and this link for more variations on Fillomino puzzles. If you are new to this puzzle type, here are our easiest Fillomino puzzles to get started on. More Fillomino puzzles can be found in The Art of Puzzles and in Fill o’ Fillomino by Grant Fikes.