(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
Today’s Mathrax has a powerful theme that might grab your attention and not let go. Can you get away from all the ten-tacles?

PDF

or solve online (using SudokuPad)

Theme: Ten-tacles

Author/Opus: This is the 150th puzzle from Clover, part of the Genuinely Approachable Sudoku (GAS) team.

Rules: Standard Sudoku rules (insert a number from 1 to 9 into each cell so that no number repeats in any row, column, or bold region). Also, some of the intersections of four cells are marked by a circle. If a circle contains a number and an operator, the number must be the result of the operation applied to both pairs of diagonally opposite cells. If a circle contains an “E” that indicates all four cells around the circle must be even.

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 6:30; One party hat (🥳): 12:00. All other solvers earn a 🦕: tentacular Tanycolagreus.

Thomas Hits the GAS (highlight to view): 2:23, with SudokuPad replay file shared as a download for now (requires loading via settings menu with improvements expected before people should use this regularly).

Solution: PDF; solving video with explanation to be added later from GAS team.

Note: Follow this link for other less common variations of Sudoku.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Daily GAS discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.