Puzzles

Puzzles that train how you think

Each puzzle here teaches a way of reasoning you can reuse: notice a pattern, test it, and explain why it works.

Choose a puzzle

LogicSudokuLearn five techniques step by step, then practise with hints that show the reasoning, not the answer.Start Logic · PicturesNonogramReveal origami and Rubik's Cube pictures cell by cell while learning five techniques that show which cells are certain.Start Logic · ArithmeticCalcudokuPractise mental arithmetic and logic together: cages that must make their number, five techniques, and a kids' mode with only + and −.Start Paper puzzlesTangramPrint your purchased PDF kit once. Choose a challenge here and build it with your paper pieces.Start Paper puzzlesPentominoPrint your purchased PDF kit once. Choose a challenge here and build it with your paper pieces.Start Strategy & recursionTower of HanoiPlay with 3–5 disks, ask for a hint from your current board, and learn the recursive strategy through two short animations. Open a step-by-step example whenever you need it.Start