Puzzles for the classroom

Everything here is free, needs no accounts and runs in any browser — on the board, on student laptops or on tablets.

Ways to use them

Starter or plenary. A 4×4 Sudoku, a Magic Sum or one CodeBreaker code takes five minutes and gets everyone reasoning.
Show the thinking. Put a puzzle on the projector and use the step-by-step solver to explain each deduction, one step at a time.
Solve together on Slate. Send to Slate opens the puzzle as a board on the free Slate whiteboard, where you can mark it up with the class and share it live to students' devices.
Differentiate. Every game has four difficulty levels and several grid sizes — give each group the right challenge.
Maths through games. Magic Path covers 81 number-property rules; BODMAS practises order of operations; Calcudoku and Kakuro practise arithmetic facts.

Do students need accounts?

No. Share the link; every page works straight away in any browser.

How do I solve a puzzle with the whole class?

Generate a puzzle, then press Send to Slate to open it on the free Slate whiteboard, where you can mark it up live and share it with students.

Can I explain the solution step by step?

Yes — press Send to Solver in a game, then step through the solution on the projector; each step says which rule it uses.