KenKen — 3×3

A3×3 grid with digits 1 through 3. Every row and column must contain each digit exactly once — the Latin square constraint. Cages use addition only, so you just need to find combinations that sum to the target.

With only three possible digits per cell, you can often solve these by pure elimination: if a row already has a 1 and a 3, the remaining cell must be 2. These puzzles teach you the fundamental mechanics before the arithmetic gets harder. Once the 3×3 feels routine, move to medium for 4×4 grids with mixed operations.