How do I explain sudoku to a child?

Every row, every column and every box must have each picture (or number) once. Find a row with only one gap first: there is only one picture it can be.

Which size should I start with?

Picture sudoku for Foundation and Year 1, numbers 4×4 next, then 6×6, and 9×9 for confident older children.

Does every puzzle have one answer?

Yes. Each puzzle is checked by a solver as it is made, so there is always exactly one solution and children can reason their way to it.

Are answer keys included?

Yes, at the end of the PDF, with the missing pictures or numbers in red.

Sudoku for Kids: Picture Sudoku and 4×4, 6×6 and 9×9 Puzzles

Logic, not guessing

Sudoku has no arithmetic in it: it is pure reasoning. Children learn to look for the place with the fewest possibilities and to check every row, column and box, which is the same careful thinking good mathematicians use.

Picture sudoku first

Four pictures in a 4×4 grid is a gentle start for children who can’t yet hold numbers in their heads. They can draw the pictures or cut and glue them in.

In the Australian Curriculum

All yearsCritical and Creative Thinking, one of the general capabilities, covers the kind of step-by-step reasoning sudoku asks for.
FoundationExplaining or showing reasoning appears from the first year of school, for example when comparing collections (AC9MFN03).

Sudoku is not part of any syllabus, but it is a useful early-finisher task and a good brain break. Picture sudoku gives Foundation and Year 1 children a reason to explain their thinking out loud: “it can’t be that one, it’s already in this row”.

For older students, ask them to write down the first square they filled and why. That turns a puzzle into a short piece of mathematical reasoning they can share with the class.

Summarised in our own words from the general capabilities and the Australian Curriculum: Mathematics, Version 9.0 (ACARA).