The Number Devil

The international best-seller that makes mathematics a thrilling exploration.
In twelve dreams, Robert, a boy who hates math, meets a Number Devil, who leads him to discover the amazing world of numbers: infinite numbers, prime numbers, Fibonacci numbers, numbers that magically appear in triangles, and numbers that expand without . As we dream with him, we are taken further and further into mathematical theory, where ideas eventually take flight, until everyone-from those who fumble over fractions to those who solve complex equations in their heads-winds up marveling at what numbers can do.
Hans Magnus Enzensberger is a true polymath, the kind of superb intellectual who loves thinking and marshals all of his charm and wit to share his passions with the world. In "The Number Devil," he brings together the surreal logic of Alice in Wonderland and the existential geometry of Flatland with the kind of math everyone would love, if only they had a number devil to teach it to them. Hans Magnus Enzensberger is the author of many highly lauded books, including "Civil Wars: From L.A. to Bosnia." He lives in Munich.
Rotraut Susanne Berner is an illustrator who lives in Heidelberg.
Michael Henry Heim is a prize-winning translator who teaches at UCLA.
In twelve dreams, Robert, a boy who hates math, meets a sly, clever number devil, who leads him to discover the amazing world of numbers: infinite numbers, prime numbers, Fibonacci numbers, numbers that magically appear in triangles, and numbers that expand without end. As we dream with him, we are taken further and further into mathematical theory, where ideas eventually take flight, until once-unfamiliar or difficult mathematical theories and principles become crystal clear. Hans Magnus Enzensberger is a true polymath, the kind of superb intellectual who loves thinking and marshals all of his charm and wit to share his passions with the world. In "The Number Devil," he brings together the surreal logic of "Alice in Wonderland" and the existential geometry of "Flatland" with the kind of math everyone would love, if only they had a number devil to teach them. "Charming and seductive . . . We might all learn more if we each had an Enzensbergian devil to beguile us into a dream and] to give us a glimpse of the beauty and power of mathematics."--John Allen Paulos, "The New York Review of Books"
"Rare and glorious."--Michael Pakenham, "The Baltimore Sun"
"Adults who know a little about math will find this book as enlightening as younger readers will."--Martin Gardner, " Los Angeles Times"
"This is one devilishly good book for math fans and math phobes alike. It is exactly the book folks are always looking for, wringing their hands and saying, 'Why aren't there more books that show the fun and imaginative parts of math?' Well, here is that book--full of the dreamlike beauty and power of math in a form that most anyone can understand. Guaranteed to send you to Number Heaven/Number Hell (which, as every kid has always known, is one and the same)."--Jon Scieszka, author of "The Math Curse "
"Children and their parents will find this to be a devilishly clever and instructional romp through mathematical history and theory. Hans Magnus Enzensberger delights and informs in equal measure."--Peggy Kaye, author of "Games for Math" and "Games for Learning"
"Self-described math-phobe Robert begins having surreal dreams in which he encounters a number devil, who teaches him, just for starters, the crucial importance of zero and how to make all numbers out of ones. More difficult concepts are deliberately repeated in several dreams; occasional additional problems are provided for greater challenges. Infinitely more fun than the usual word problem assignment."--"Horn Book" Excerpt from" The Number Devil"
by Hans Magnus Enzensberger
In time Robert grew accustomed to dreaming of the number devil. He even came to look forward to it. True, he could have done without his know-it-all attitude and his temper tantrums--you could never tell when he'd blow up and yell at you--but it was better, so much better, than being swallowed by a slimy fish or sliding down and down into a black hole.
Besides, Robert had made up his mind to show the number devil that he was no fool. You have to put people like him in their place, Robert thought as he got ready for bed one night. The big ideas he has about himself--and all because of a zero. He wasn't much more than a zero when you got down to it. All you had to do was wake up and he was gone.
But to put him in his place Robert had to dream of him, and to dream of him he had to fall asleep. And Robert suddenly noticed he was having trouble doing so. For the first time in his life he lay awake in bed, tossing and turning.
"What are you tossing and turning for?"
All at once, Robert realized his bed was in a cave. There were weird paintings of animals on the stone walls, but he had no time to study them because the number devil was standing over him, twirling his walking stick.
"Rise and shine, Robert " he said. "Today's our division day."
"Must I?" Robert asked. "You might have at least waited until I was asleep. Besides, I hate division.
"Why?"
"When you add or subtract or even multiply, things come out even. What bugs me about division is that you get this remainder."
"The question is when."
"'When what?"
"When you get a remainder and when you don't. That's what counts. You can tell just by looking at them that some numbers can be divided evenly."
"Right. Like even numbers, which can all be divided by two. No problem. I'm pretty good at threes as well:
9 / 3
0 15 / 3
and so on. It's like multiplying in reverse:
3 x 5 = 15
becomes
15 / 3 = 5
I don't need a number devil for that. I can do it on my own."
Robert shouldn't have said that. The number devil, his mustache quivering, his nose reddening, his head growing bigger