Arrow Sudoku rules and puzzles

The case notes

Subtract an overlapping cage from an arrow

This arrow and this Killer cage overlap. The arrow’s circle is nine. The little cage at the far end of its shaft sums to four. Watch a worked example, then try the idea in a puzzle.

Put it into practice

Arrow = 9 · cage = 4

This arrow and this Killer cage overlap. The arrow’s circle is nine. The little cage at the far end of its shaft sums to four.

Whole shaft = 9

The three shaft cells together equal nine. Think of that as the whole sum. The two caged shaft cells are one known part of it.

9 − 4 = 5

The cage gives that shared part a total of four. Subtract its four from the arrow’s nine. Only the first shaft cell remains.

The uncaged shaft cell is 5

So this cell is five. When two sum clues overlap, remove their shared cells and see what the difference tells you.

Read the transcript

This arrow and this Killer cage overlap. The arrow’s circle is nine. The little cage at the far end of its shaft sums to four. The three shaft cells together equal nine. Think of that as the whole sum. The two caged shaft cells are one known part of it. The cage gives that shared part a total of four. Subtract its four from the arrow’s nine. Only the first shaft cell remains. So this cell is five. When two sum clues overlap, remove their shared cells and see what the difference tells you.

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