Consecutive Sudoku Puzzle Books - 400 Easy to Master Puzzles 6x6 (Volume 1)

Sudoku (also known as "Number Place") is a placement puzzle.

The puzzle is most frequently a 6 x 6 grid made up of 3 x 2 subgrids (called "regions").

Some cells already contain numbers, known as "givens".

The goal is to fill in the empty cells, one number in each, so that each column, row, and region contains the numbers 1 through 6 exactly once.

Each number in the solution therefore occurs only once in each of three "directions", hence the "single numbers" implied by the puzzle's name. In Consecutive Sudoku ("1-away Disallowed Number Place"), all the places where orthogonally adjacent cells are consecutive numbers have been specially marked.