Quad Sums
Solve online in Penpa+ (thx Nick Smirnov!)
Place the digits from 1 tot 9 in every row, column and 3x3-block. A circle at a corner implies that one digit is the sum of the remaining three digits at that corner.
Solution code: Column 4, followed by column 6.
on 14. July 2022, 10:23 by Richard
Added link and tag for online solving. Thx Nick!
on 13. December 2020, 07:28 by Nick Smirnov
Penpa:
https://git.io/JIy6R
on 9. July 2016, 14:27 by Richard
Nee, da's lekker. Een lagere waardering toekennen omdat je de instructies niet goed leest! :-)
on 22. January 2015, 15:26 by Rollo
Ganz tolles Rätsel, die beiden Quadrate mit vier Punkten sind 'ne Wucht!
on 20. January 2015, 06:07 by Richard
Corrected the solution code description in the German version. The code contains columns 4 and 6 instead of rows 4 and 6. The English version was already correct.