The mathematical puzzle CalcuDoku is fast becoming very popular. Solving one takes a combination of Sudoku-style logic reasoning and basic math skills, making it a much more interesting and satisfying puzzle. However, it is still not easy to find challenging CalcuDoku puzzles. This book has only those: 101 puzzles, each of which will keep even experienced puzzlers busy for at least half an hour. Included are, for example, puzzles using zero, the modulo operator, many 10x10 puzzles, one 12x12 puzzle, and even one 15x15 puzzle! The puzzles are printed at a large size, leaving plenty of space for notes. The third edition has twenty of the popular new "twin" puzzles: pairs of puzzles with the same solution, but with a different layout, so you can use clues from each puzzle to solve both.