Hard 6×6 Number Sudoku
Twenty squares to fill in each grid and very few easy starts: this hard 6×6 number sudoku suits children aged 8-10 who solve the medium level without help.
2 A4 pages · for home and classroom use
Sudoku 6×6 — hard
How to use this worksheet
- In the left puzzle the second row shows only a single number, 1, and the number 6 is printed just once in the whole grid.
- At the start, only two squares of the left puzzle have a single possible number, and both turn out to be 3s. Find them first.
- When no square is obvious, switch the question: pick a number and ask where it can go in one row, column or box.
- Check both puzzles against the solution page.
What this worksheet teaches
Each 6×6 puzzle has six boxes of 2 rows by 3 squares, and every row, column and box must hold 1 to 6 once. With only 16 numbers given, most squares start with several options, so children combine two views: one square and one number. Each puzzle has exactly one solution reachable by logic alone, which rewards patience.
Hidden singles: where can this number go?
Sometimes a square has several possible numbers, yet one of those numbers has nowhere else to go in its row, column or box. That number must go there, even though the square alone did not show it. Solvers call this a hidden single. On hard grids, hidden singles are often the fastest way forward.