Karnaugh Maps

A K-map arranges the truth table in Gray-code order, so neighbouring cells differ by one variable. Group adjacent 1s in rectangles of 1, 2, 4, 8… cells (groups can wrap around edges); each group becomes one product term with the changing variables removed.

Example: $F = \bar{A}B + AB$ — the two cells are adjacent, so $F = B$.

"Don't care" cells (X) can be included in a group if that makes it bigger. For more variables, use the Quine–McCluskey algorithm or software.