In spite of the fact that logic puzzles are based on words and ideas, there is an amazing variety to be found. There are fascinating number puzzles, too. Indeed, numbers themselves are puzzles: There are ten digits and twenty-six letters, but the variety of words is finite while numbers are infinite. Words and numbers are both handled by the left hemisphere of the human brain and processed in the same way, regardless of their seeming differences. Thus traditional formats for word-based puzzles, such as crosswords and word searches, also get their own numeric treatments.