Scottish Sum Line. The white lines are Scottish Sum lines, where starting from one end (which end is to be deduced by the solver), the third digit along the line is the sum of the previous two digits and then the following numbers are the sum of their previous two digits. Where the addition results in a number greater than nine, then only the second of the two digits is placed and this number is used for the ongoing additions. (eg 52796516 etc).
Black dots separate adjacent digits that are in the ratio of 2:1 and white dots separate adjacent digits only one apart.
(Hint - there are six 'secrets' of Scottish Sum lines. One of them will help you solve the puzzle in ten minutes. If you dinnae ken it you may tak a wee bit longer)
Solve online:Sudokupad
version for visually impaired
Solve online:Sudokupad
Solution code: top line of puzzle
on 13. October 2025, 11:40 by billybeth
added additional link
on 11. October 2025, 13:35 by bboom
Fun little puzzle! I guess 'Fibonacci line' might be a more common way to describe the line, but it is clear enough either way.
And I never discovered more than one of the six secrets... But that was still enough to solve it fortunately.
on 11. October 2025, 11:27 by QuiltyAsCharged
I have no idea why this received some negative votes, but it's a great puzzle and worth trying! Scottish Sum Lines have interesting properties to discover
on 28. September 2025, 05:25 by billybeth
tidied up ruleset
on 22. September 2025, 09:12 by billybeth
added link
on 18. September 2025, 12:15 by billybeth
tidied up page
on 18. September 2025, 12:14 by billybeth
tidied up page
on 18. September 2025, 02:22 by VicJameson
Wow, never came across a Scottish Sum Line before. I definitely figured out some of the secrets, and stumbled into a couple more.
Having to work it all out from scratch did mean that it took me a little longer than 10 minutes. But less than an hour (by a minute and a half) isn't terrible for me.
Thanks for the great puzzle.
on 17. September 2025, 21:27 by billybeth
add image
on 17. September 2025, 20:17 by billybeth
image
on 17. September 2025, 20:16 by billybeth
added image
| Difficulty: | ![]() |
| Rating: | 77 % |
| Solved: | 28 times |
| Observed: | 1 times |
| ID: | 000P8K |