'My First Sudoku: 130 Beginner Puzzles for Kids - 4x4, 6x6, 8x8 and 9x9 Grids'
The perfect book for children starting to do Sudoku Start out with easy 4x4 'kid grids' that get gradually harder, before moving on to 6x6, 8x8 and conquering full-size 9x9 grids. Each grid size has 2 to 3 levels of challenge, and this progressive