The inescapable Su Doku craze reaches key stage 2 in a couple of new books. Junior Su Doku offers 120 puzzles, using shapes and letters as well as numbers. It builds up the reader's confidence by beginning with 4 x 4 grids, then moving to 6 x 6 and the full challenge of 9 x 9.
Murderous Maths: Su Doku has slightly fewer puzzles, but many more helpful hints, advice on strategies, stories, cartoons and puns. It also contains the 22-digit expression that represents the number of different possible 9 x 9 puzzles. The craze has a long way to go. Junior Su Doku costs pound;3.99 (Wizard Books) and Murderous Maths: Su Doku costs pound;2.99 (Scholastic).