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Classic Sudoku · 4×4 · Easy
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Classic Sudoku
Classic Sudoku is the most popular form of sudoku. Fill the grid so that each number appears exactly once in every row, column, and box. It is a…
LEVELAll levelsBUILDSLogic, concentration, number sense, pattern recognition, deductive reasoning
Also known as: Standard Sudoku, Number Sudoku
ClassicHOW IT WORKS
What is Classic Sudoku?
Classic Sudoku is the most popular form of sudoku. Fill the grid so that each number appears exactly once in every row, column, and box. It is a fun and effective way to build logic, concentration, and problem-solving skills.
THE RULES
Simple rules, satisfying logic
Keep these rules in mind while solving.
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Fill every empty cell with a number.
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Each row must contain every number exactly once.
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Each column must contain every number exactly once.
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Each box or region must contain every number exactly once.
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Do not repeat a number in any row, column, or box.
STEP-BY-STEP
How to start solving
A calm path from the first observation to the final answer.
- 1
Scan the grid
Begin by looking across all rows, columns, and boxes to find the areas with the most given numbers. These are usually the easiest places to start.
- 2
Find missing numbers
Choose one row, column, or box and identify which numbers are missing. Compare the missing numbers with neighboring rows, columns, and boxes to see where each one can go.
- 3
Use elimination
For each empty cell, eliminate any numbers that already appear in the same row, column, or box. If only one number can fit, write it in.
- 4
Look for single possibilities
Sometimes a row, column, or box has only one place where a certain number can go. When that happens, place the number there and continue checking the grid.
- 5
Repeat and progress
Keep repeating the process of scanning, checking missing numbers, and eliminating impossible options. Each correct placement creates new clues for the rest of the puzzle.
- 6
Finish the puzzle
Continue until every cell is filled and each row, column, and box contains the required numbers exactly once.
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