URN · Corner logic

A deduction-only experiment. The board stays still: fill the missing corner digits using the hub rules and tile totals.

Gold hubs A, B, C: the six nearby corner digits must contain 1–6 exactly once.

Tile totals: the three digits on each triangle add to its Σ clue. Digits may repeat within a tile. White digits are fixed; gold digits are your entries.

White: givenGold: editableΣ: tile total

Pencil notes

Select a gold circle, then enter a digit from 1–6. You can also use the number keys; Backspace clears a cell.

All 16 triangles are filled in this fixed-board experiment, so each hub has six digits. Each puzzle is checked to be solvable by deductions without guessing. Navigation saves your progress on this device. The moving versions remain available above, now with animated edge flips.