Number Enigmas: Over 125 Challenging Exercises! in Bloomington, MN

This compilation is for those who want to maximize their mental arithmetic skills and sharpen their logical “intuition.” No matter what your level of ability, a carefully graded series of challenges ensures that this book has plenty for everyone. Time limits further add to the fun.
Generally, logic puzzles are based on words and ideas, but there is an amazing variety of fascinating number puzzles, too. Indeed, numbers themselves are puzzles: There are twenty-six letters and only ten digits, yet the variety of words is finite while numbers are infinite.
Over 125 full-color puzzles with solutions fully explained
Each puzzle is carefully rated for difficulty
Expertly crafted by our crack team of puzzle-constructors, this volume offers a spectacular range of challenges
A colorful gift, and a must-have for every puzzler