Sudoku for Kids
Real, freshly generated sudoku puzzles — every one is checked to have exactly one answer. Start with a gentle 4×4, grow into the full 9×9, and print a sheet for the whole class.
The one rule of sudoku is that every row, every column and every box must hold each number once and only once — 1 to 4 in a 4×4 grid, 1 to 6 in a 6×6 and 1 to 9 in a 9×9 made of nine 3×3 boxes. Every puzzle here is generated fresh and proved to have exactly one answer.
Puzzle setup
Pick a grid size and level, then press New puzzle.
Build a printable sheet
Fresh puzzles, laid out for A4 with an answer key at the end. Every puzzle has exactly one answer.
Every puzzle has exactly one answer
The generator builds a complete, legal grid first, then takes numbers away one at a time — and after every single removal a solver proves the puzzle still has one unique answer. If it does not, the number goes straight back.
Choose size and level
4×4 for Class 3, 6×6 for Class 4–5, the full 9×9 from Class 6 upwards.
Tap a square, type a number
Use the keypad, the keyboard, or pencil notes when you are not sure yet.
Get a hint, not the answer
A hint fills one square and tells you the reason, so you learn the method.
Print for the class
Up to 16 fresh puzzles with an answer key, ready for A4 paper.
The one rule of sudoku
Fill the grid so that every row, every column and every box holds each number once — and only once.
- 4×4 grid → numbers 1–4, boxes of 2×2
- 6×6 grid → numbers 1–6, boxes of 2 rows × 3 columns
- 9×9 grid → numbers 1–9, boxes of 3×3
Technique 1 — the only choice
Look at one empty square. Cross off every number that already appears in its row, its column or its box. If only one number survives, that square is solved.
square = the only number left
Technique 2 — the only place
Now flip it around. Take one number, say 7, and one box. If 7 can only fit in a single empty square of that box, write it there — even if that square still has other possibilities.
This is the step that unlocks most Medium puzzles.
Technique 3 — pairs and pointing
Two squares in a row that can only hold 3 or 5 form a pair: 3 and 5 are then impossible everywhere else in that row. And if a number fits only along one row inside a box, it is pointing — rub it out of the rest of that row.
Hard puzzles on this page are built to need exactly this kind of thinking.
Why sudoku helps in maths
Sudoku has no arithmetic in it at all — it trains the reasoning maths needs: scanning, elimination, holding several facts in mind and checking your own work. A 4×4 grid is a perfect first logic lesson for Class 3.
Seeds: the same puzzle, again
Every puzzle has a seed number. Note it down and anyone can rebuild the identical grid later — handy when the whole class should solve the same puzzle, or when you want yesterday's puzzle back.
Sudoku for Kids — your questions
What are the rules of sudoku?
Fill the grid so that every row, every column and every box contains each number exactly once. A 4×4 grid uses 1 to 4 in 2×2 boxes, a 6×6 uses 1 to 6 in boxes of two rows by three columns, and a 9×9 uses 1 to 9 in nine 3×3 boxes. No arithmetic is involved at all.
Which sudoku size should a child start with?
A 4×4 grid is the right first step, usually around Class 3 — it has only sixteen squares, so a child can finish one in a couple of minutes and see the logic clearly. Move to 6×6 around Class 4 or 5, and to the full 9×9 from Class 6 upwards once scanning a nine-square box feels comfortable.
How do I solve a sudoku puzzle step by step?
Start with the only choice: pick an empty square and cross off every number already in its row, its column and its box — if one number survives, write it. Then try the only place: take one number and one box, and if it can fit in a single empty square of that box, it belongs there.
What is a naked pair in sudoku?
When two squares in the same row, column or box can only hold the same two numbers — say 3 and 5 — those two numbers must occupy those two squares between them. So 3 and 5 can be crossed off every other square in that row, column or box. This is the step that usually unlocks a Hard puzzle.
Does every sudoku puzzle have only one answer?
A properly made one does, and every puzzle on this page is checked. The generator builds a complete legal grid first, then removes numbers one at a time, and after each removal a solver proves the puzzle still has a unique answer. If it does not, the number goes straight back in.
Can I print sudoku puzzles for a class?
Yes. Choose the size, the level, how many puzzles per page and how many pages — up to sixteen fresh puzzles in all — then add an answer-key page and a name-and-date line. Four easy puzzles per page make a good two-minute warm-up; keep an Expert sheet for the maths club.
Does sudoku actually help with maths?
Sudoku contains no arithmetic, but it trains exactly what maths needs: systematic scanning, elimination, holding several facts in mind at once and checking your own work before committing. A 4×4 grid makes a very good first lesson in logical reasoning for a Class 3 child.