(But they can take comfort in knowing that no more than one will occur in any single puzzle.)

    Following the enthusiastic reaction to Mathematical Puzzles: A Connoisseur's Collection, Peter has compiled a new collection of elegant mathematical puzzles to challenge and entertain the reader. The original puzzle connoisseur shares these puzzles, old and new, so that you can add them to your own anthology. This book is for lovers of mathematics, lovers of puzzles, lovers of a challenge. Most of all, it is for those who think that the world of mathematics is orderly, logical, and intuitive-and are ready to learn otherwise! A pdf with errata is updated by the author and can be accessed here

    Along the top and left side of the grid are numbers that refer to the columns and rows: these are the keys to a code revealing which and how many squares to fill in. It just takes a little logic, concentration, and patience to figure it out—the process is a lot like sudoku, actually, where you work with numerical clues. But the result is something to show off, because out of the mix of black and white squares comes images of a bus, cat, pineapple, samurai, sphinx, and even James Dean!

    It features illustrations in cartoon style along with maps and guides which helps children experience the absorbing adventure.

    And although each puzzle maintains the normal 9x9 grid and follows the basic rules of the game, every style adds an additional restriction to intensify the challenge. In “Worms,” for example, swirly, squirmy shapes fill the grids; the numbers increase as you work your way from head to tail. “Even/Odd” features squares in two colors, depending on whether the number to fill it is even or odd. And in “Positional Board,” no two of the red squares can be the same number. They’re all lots of fun!