Sudoku is a popular number puzzle game. It consists of a 9x9 grid, divided into 9 smaller 3x3 grids called regions or boxes. The goal of Sudoku is to fill in the entire grid with numbers from 1 to 9.
The puzzle starts with some numbers already filled in as clues. Your job is to use logic and deduction to figure out where the remaining numbers should go, following the rules mentioned above, until the entire grid is filled correctly. Sudoku puzzles come in different levels of difficulty, and they require problem-solving and critical thinking skills to solve.
Each row in the 9x9 grid must have all the numbers from 1 to 9, and no number can be repeated in a row.
Each column in the grid must also have all the numbers from 1 to 9, with no repetitions.
Each 3x3 region must contain all the numbers from 1 to 9 without duplicates.
Look for the easiest numbers to place first. These are typically the 1s and 9s because they have the fewest possible placements due to the rules.
Examine rows, columns, and regions to see if a number can only fit in one specific spot. If a number is missing in a row, column, or region, and there's only one empty space left for that number, you can place it there.
It's helpful to use small numbers (pencil marks) in the corner of each square to note down the possible numbers that could go there. This helps you keep track of your options.
Find situations where a number can only fit in one row, column, or region within a larger grid. This process of elimination helps narrow down the possibilities.
Hidden singles are numbers that are the only possible choices in a row, column, or region but are not immediately obvious. Look for squares that could only have one possible number based on the rest of the filled-in numbers.
When you notice two or three cells in a row, column, or region that can only contain the same set of two or three numbers, you can eliminate those numbers from the rest of the row, column, or region.
Crosshatching means checking each region for a specific number and seeing if it can only go in one row or column within that region. This helps to place numbers.
Look for two or three squares in a row, column, or region that can only contain the same pair or triple of numbers. This allows you to eliminate those numbers from other squares in the same row, column, or region.
The more you practice, the better you'll become. Start with easier puzzles and gradually work your way up to more challenging ones.
Sudoku can be a challenging puzzle, and sometimes it takes time and multiple passes to make progress. Don't be discouraged if you get stuck; take a break and come back to it with fresh eyes.