The term refers to the method of engaging with a number-placement puzzle. A standard example involves a 9×9 grid subdivided into nine 3×3 blocks, partially filled with digits from 1 to 9. The objective is to complete the grid so that each row, each column, and each block contains every digit from 1 to 9 without repetition.
Engaging with this type of puzzle enhances logical reasoning and pattern recognition skills. Its widespread popularity provides a stimulating mental exercise accessible to individuals of varying skill levels. Historically, variations of number placement puzzles have existed for over a century, evolving into the modern form recognized globally.
The following sections will detail the core strategies for solving this type of puzzle, common errors to avoid, and resources for further exploration.