Challenging Arithmetic Puzzles

Each volume in this series has 50 puzzles each of Mathrax, Kakuro, Calcudoku, and Sukrokuro (all 9×9 grids). The puzzles progressively increase in difficulty and are intended for anyone looking for an intense challenge. The solutions to all puzzles are provided at the end of the book, including a cheatsheet of sum combinations for Kakuro and Sukrokuro puzzles. There is one puzzle on each page and ample space to work on the sums. The print is relatively large and easy on aging eyes.