Dissect the diagram into areas and write a number in every field. The numbers in one area have to be the same and have to tell the number of fields in that area. Areas of same size my not touch horizontally or vertically, but diagonally. Given numbers may belong to the same area, and it's possible that there are areas, where no number is given - even with larger numbers than the ones shown.
Solution code: Row 9, followed by Column 5. Enter only the last digit for any two-digit number.
on 4. January 2023, 05:37 by TJReds
penpa link: https://tinyurl.com/2lcqqybl
(For those that may prefer it)
on 24. October 2022, 10:40 by Drawoon
pzv: http://pzv.jp/p.html?fillomino/10/10/l2hag2i7h9k6h8k6h7h7h7h6hah4h5h8h6h4h8k3h2k2h1i1g1h3l
on 11. June 2017, 10:08 by ibag
Schön!