These are matrix puzzles: 3×3 grids where the missing value follows from the relationship between rows, columns, or both. The challenge isn't arithmetic — it's figuring out which relationship applies.

Check rows first (does the third cell = first × second?). Then columns. Then try sums per row being equal. If nothing works, look at the diagonals or see if each row applies a different operation to a common base. These are genuinely hard, and getting one right feels good.