The Number Devil: A Mathematical Adventure

This book makes maths fun, even for those little people who believe it to be a laborious trudge through treacle. In fact, that would describe Robert, the main character in this book. He has been struggling with maths for as long as he can remember. One night, he dreams that he meets a little devil, The Number Devil, who teaches him, as he sleeps, all sorts of useful tricks with numbers.

When you enjoy something, and gain immediate benefit, you obviously learn more.

My Dad made all aspects of mathematics enjoyable for me from a very early age, almost from when I could walk and talk, by relating what we were seeing in the real world to mathematics in some way. He didn't label the principles as geometry, algebra, arithmetic, and so on. He just mde it all part of my world. Consquently, I never scored less than 90% in any maths test or exam in my life. I just enjoy maths as much as living.

The same holds for Robert, and for readers of this lovely little book.

My grandson was hating maths, and couldn't see the point. When I took him through the first chapter of The Number Devil, he could suddenly, and effortlessly, multiply 11 by 11, 1111 by 1111, 1111111 by 1111111 and so on. He also learned, through self motivation inspired by his "new trick" to multiply any number you could throw at him by eleven.

This may seem a small step, but you can believe me when I tell you that it was a massive step for Alfie. Furthermore, he couldn't wait to get to school the next day to show his new skills to his class-mates and his teacher.

That wasn't all. There was much more magic to be revealed in this great little book, and I would encourage anyone to share it with their children, even if they are already very numerate. It just gives them, and you, a new spin on an ancient subject.

The Number Devil is an interesting take on number theory, giving insights into these theories in a relatively simple way for anyone to understand. The book follows the main character, Robert, who is 12, through 12 nights of dreams in which he had never experienced before. Robert meets a number devil in his dreams who teaches him about all the fantastic world of numbers and the many concepts of mathematics. Each dream houses a new idea which the number devil teaches Robert. Some of these include fractions, square roots, square numbers, Fibonacci numbers, and prime numbers, along with many more. The number devil introduces these topics in fun, interesting, and magical ways to Robert, as he’s someone who never enjoyed math, or numbers for that matter.
The book is great for children who are learning about math, or who love the discipline of mathematics, or even for those who may be struggling with numbers. Though it is helpful, it could also be confusing – which may stem from the age I am and the knowledge I already have, but the author uses random words for things which have actual names in the field of mathematics, which was a bit bothersome while reading. For example, the number devil in Robert’s dreams calls square roots, rutabagas and prime numbers, prima donnas. While this may help children, I think the real names of these concepts are important as well and they should be learned, but this may also be because of my age and the knowledge I already have.
The Number Devil is a great book for students of a younger age who are either interested in Mathematics, or for those who are struggling with mathematics, or for anyone in-between, but I would not recommend for anyone with previous knowledge of the concepts introduced, as the made up names for things gets a bit annoying. While that is true, it could deem useful for students of a younger age who are learning about these concepts for the first time, as it lays out the ideas in a nontraditional way, which many times is helpful for some students. I read this book for a college education course, and if I were teaching mathematics to a younger age group, it would be easy to include this book into a lesson plan, as each chapter dives into a new concept. This would be easy to come up with lesson plans for while students read the chapter before the class outlining the concept. While I don’t suggest it as a book to read for people with knowledge of these concepts, it can be a great learning tool for students currently learning the concepts held in the book.

In Hans Magnus Enzensberger's The Number Devil, a boy and a devil interact with each other through various dreams, while looking at different mathematical concepts. The author creates a story of Robert, a young boy with below average math skills, and his trip through the world of mathematics with the help of the number devil, an elderly red man who leads Robert to mathematical revelations. At the start of their relationship Robert questions the elderly red man and is unsure how he should respond to the devil's actions, disregarding his comments. As their story unfolds, the number devil shows Robert many mathematical concepts in their adventures.

As the story progresses, Robert becomes more interested in what the Number Devil is showing him. At first Robert is reluctant to work with the number devil. He is in no mood to deal with the number devil or his numbers. Eventually he becomes accustomed to dreaming about the little red man. In the fourth chapter, he stops dreaming of the number devil for a while and waits for the number devil to reappear in his dreams. He looks forward to the dreams where he and the number devil would have the chance to discover more truths and tricks of math. In the last chapter when Robert stops dreaming again, he finds himself sleeping sounder than he has in a while. He does not like the idea that the number devil may have forgotten him. Because of his maturing relationship with the number devil, Robert grows to enjoy and respect numbers, something he probably did not think would occur in his life.

I found it interesting how the author chose to portray the mathematician as a devil. Typically, when people think of a devil they think of someone who has tricks up their sleeves. This seems fitting as he represents mathematics. If you are not familiar with the nature of numbers may consider math to be a bunch of tricks. Though most of the math content the child reads in this book may be challenging for young children to understand, the book is written clearly and simply. It brings up thought-provoking issues in mathematics, which can also appeal to adult readers as well as young readers. These issues not only include math topics but also how math is portrayed in the global society.
The author shares his knowledge and creativity through different settings, creating a book that attracts both children and adults. Like an onion, The Number Devil is full of juicy math layers that inspire people to examine math in their world. This book is written for all to enjoy and I highly recommend it to readers of all ages.

I loved THE NUMBER DEVIL! I've always thught that math was really interesting and exiting, but this book made me even more sure.
THE NUMBER DEVIL is about a boy named robert who starts to dream about a number devil. In his dreams the number devil teaches him all sorts of interesting facts and shortcuts to math problems in an interesting and funny way.
I would have read THE NUMBER DEVIL in about 2 days, but some of the things explained in the book were confusing, so it took alot longer. One thing about the square rute, or rutabaga, of 2 was really confusing and I had to read it about 10 times before it made sense, and there are some things that I still dont get. One thing I thought was weird was I always had to flip back and re-read some of the facts for other things to make sense. Though I have alot of complaints, I like math, and still really enjoyed this book, and would reccomend it to anyone who likes math, or hasn't figured out whats so interesting about it.

The Number Devil by Hans Magnus Enzensberger is a pleasant introduction for children to the world of number theory and theoretical mathematics. The book lives on the idea that the math problems people see in school is not real mathematics, that numbers live in a secret, magical world on their own. While it may not have a clear target audience and fails to validate some of its later claims, it does a wonderful job of introducing some fairly complex mathematical concepts in a simple, easy to understand way.
The Number Devil tells the story of its titular character entering the dreams of a young boy, Robert, who dislikes his math class and teacher. The Number Devil, however, shows Robert that numbers are not evil and are in fact quite magical. From the triangle numbers to “rutabagas” and infinite series, there are numerous secrets that can be found without doing complex calculations or caring about pretzels (a favorite topic of his teacher). Robert learns to love numbers and no longer fears math after completing his training with the Number Devil.
The book is written in the style of a child's story book, complete with colorful illustrations on just about every other page. This belies the deep, complex mathematical notions it is teaching to its readers. Ideas such as the traveling salesman problem, infinite series, and countably infinite sets would at the earliest likely be introduced at the high school level, yet the book is written as if it is talking to elementary school students. While it works well for the younger audience, it is too simply written for the older; high schoolers may lose interest reading at this lower reading level, even though they would have a better appreciation for the mathematics; and if they are not interested in math to start with, they may have no interest at all.
One of the books strengths in the majority of the dreams is that while the Number Devil explains things to Robert in an intuitive way, he also validates his claims similarly. However, in some of the later dreams, he does not. For instance, when discussing the 'blankety-blank' unreasonable number 1.618 . . . , more commonly referred to as the golden ratio, he tells Robert how two lines on a star within a pentagon are proportionate by precisely that factor, and does nothing to back up that claim while Robert accepts it. There is nothing really intuitive about this, and it leaves the reader to just accept it, something aspiring mathematicians should not learn to do.
Despite these couple shortcomings, this book does provide readers with a sense of wonder towards the world of numbers. Perhaps its greatest strength is that it does not fully develop all of its ideas or show all that they can do. Imagine, a student reading this in middle school, seeing the triangle of numbers, then seeing it again in high school, only now being used to expand binomials. That “Aha!” moment of recognition would catch their attention in a unique, familiar way that would be difficult for a teacher to do on their own while peaking their curiosity about what other secrets are hidden within it or the other notions such as the triangle or “Bonacci” numbers.
The Number Devil truly captures the essence of mathematical curiosity within a child's storybook. Despite being unable to hold the attention of older students and leaving some claims unexplained, it takes the reader by the hand and shows them the shimmering surface of the wonderful world of numbers, without a single sign of pretzels or word problems.

Crossing the story Alice in Wonderland with a small, red, fiery-tempered devil with a passion for numbers gives you The Number Devil, a perfect tale with funny and curious characters.
Robert hates math, and he gets irritated because his math teacher doesn't allow calculators in class. In addition to that, he has peculiar dreams all the time. Then, one night, completely out of the blue, he dreams about a Number Devil, who takes him away to a fantastic world of numbers. Robert learns all about different mathematical ideas and concepts in a fun way. Over the course of 12 different nights, Robert learns about simple math ideas like factorials, fractions, the importance of zero, and the idea of infinity. But Robert's adventures don't stop there; Robert also learns about more complex things like triangle numbers, Fibonacci numbers, imaginary numbers, and irrational numbers. The Number Devil makes up funny terms in order to explain these to Robert. Square roots are called "rutabagas," prime numbers are "prima donnas," squaring becomes "number hopping," the Fibonacci sequence is called "the Bonacci numbers, " and factorials are named "vrooms."
Did you know that you can take any even number larger than two and find two prime numbers that add up to it? The Number Devil presents different mathematical ideas to Robert, using funny things like furry calculators and coconuts. Even Robert uses what he learns in his dreams in class. For example, the Number Devil uses coconuts to show Robert what triangular numbers are. He uses the coconuts to make triangles on the ground, and he comes up with the first ten triangular numbers: 1, 3, 6, 10, 15, 21, 28, 36, 45, and 55. Next, he comes up with a little rule for triangular numbers: Any number greater than 1 can be the sum of two or three triangle numbers. Try 83, for example. It is the sum of 10 + 28 + 45.
Not only does the Number Devil show Robert different math principles, but he takes him to Number Paradise, and there Robert meets different mathematicians like Carl Friedrich Gauss (of course, the Number Devil makes up names for the mathematicians as well, so Gauss is called Professor Horrors), Georg Cantor (Professor Singer), and Leonhard Euler (Owl). Robert also meets Felix Klein (Dr. Happy Little), and he sees the famous `Klein Bottle' (the Little Bottle). The Number Devil shows how one can't tell the inside of this object from the outside!
I thought this book was very enjoyable and funny. The illustrations were amusing and the characters were hilarious. I especially liked the Number Devil himself. I would give the book an eight out of ten only because some of the concepts described were very elementary, and it became boring for me at times. Overall, I didn't learn a lot, but the little tidbits of information and the more complex ideas were interesting. I would recommend this book for all ages as a good read aloud or for a bedtime reading book. Happy reading!

The Number Devil is a fascinating read. It is about a 12 year old boy, Robert, who hates Mathematics. One night, a Number Devil appears in Robert's dream to solve his Math problems. Robert is surprised as he does not have his usual dreams. The Number Devil teaches Robert a lot of Mathematics and a close friendship develops between them.

I liked this book because you feel as if you were Robert himself. Reading the book I remembered the times when I too was struggling to cope with Mathematics. The book contains a bit of humor, fiction and sadness too. The fact that was the coolest was the triangle which the Number Devil and Robert built with numbers and the different triangles with numbers divisible by 2 and 5 in them.

The story is very well interwoven with Mathematics. So it's neither a storybook nor is it a Math textbook. It is very well written. While reading I did not feel at all like keeping the book down. It is very engrossing. It surely is a must-read.

The Book is esthetically pleasing and starts well, but ultimately it doesn't seem to take the reader anywhere. Maybe I am too old, to appreciate it. I will certainly keep the book and try it on my sons when they get older. But My feeling was that although the "Mechanics" of numbers and sequences where explained, there is no help or tools given to enable the reader to "detect" a number sequence and utilize that knowledge to solve a problem. (The hero's solution to his classroom problem seemed contrived Reminiscent of the old cliches, "with one bound he was free". How did he know to write the numbers down like that?). The Tricks of number Organization and layout that allow us to discern the patterns and to make use of them (are there such things) would in my mind make a more valuable book. The number devil reminded me of the Mathematical Prodigy Ramanujan (described in Stanislas Dehanene's Excellent Book the Number Sense), who given a number can instantly describe all the remarkable properties of it, but no one knows how he performs the task nor can emulate it.

I have little to add to the other reviewers' comments. The devil himself is not that exciting, he's no Dr. Matrix, and the dream sequences are just backdrops to the main themes. Renaming various things like factorials "vroom!" and Fibonacci "Bonacci" seems a bit silly and doesn't add a lot. But who cares? In each chapter a fascinating bit of mathematics is presented in an approachable and fun way: Pascal's triangle, combinatorial sets, infinite sets of numbers, and so on. Also, the main character acts in a realistic way: he gets annoyed, he's sometimes lazy, etc. More important, he generally asks the questions readers want to know, and in a believable way.
This is a good book to give a 6th grader with (or better yet, without) an interest in math. I'd also recommend Martin Gardner's two "Aha!" books ("Insight" and "Gotcha"), which present great puzzles and paradoxes in a single page each.

A math professor I know actually uses this book to teach a college level class and a class for advanced high school students. The book, though not a great literary piece, does introduce many different concepts from many areas of undergraduate mathematics. One potential problem with the book is that although the Number Devil mentions any facts, he never proves any of them. This presents a great oppurtunity for students as then they can prove some of the Devil's statements, like his formula for Triangle Numbers. Be warned, though, some questions that the Number Devil asks are actually still open questions in mathematics, and not even your teacher will know the answer or proof! Overall, though not a good stand-alone book, it's a great companion to a regular class that tries to introduce the students to non-calculus mathematics.

Is there a devil on your back thats been hounding you to learn those numbers? Well, there is an easier way to learn and understand numbers. With Haans Enzensberger's childrens book The number Devil, its not only fun, but makes it all look easy. Sometimes it is, other times it can be overwhelming. The number devil is a story that takes place in dreamland where a child, who hates math and numbers finds out how numbers are essential to the world we live in. He also finds out that numbers are easy to understand, so long as we take the time to understaand them. Each chapter attempts to study a number. Starting with 0 and 1, then moving to others from 2 on up. Every number is a pattern and creates more patterns. Its a matter of seeing the patter that clears up the muddle of large numbers. I found this book easy to read and fun and educational. Highly reccomended!

Well, this book was really interesting. It was alright to me, It was different from other books. This book talks about math more than any other books. It will teach you about something that you don't know anything about in math,and you will learn it easier if you do what he teaches you.
Well, not only does the book help with math,it has a lot of metephors. Well it has a lot of funny things in it. The book is really about Robet is having dreams aboout math and the The Number Devil is teaching him. He is learning things that he doesn't understand in school. Every night he has a dream, and it helps him every day he goes to school. At the end his teacher is amazed at what he can do. IF you read this book you will find out what happens.
Epiphany.

This is a great book for piquing your interest in some very interesting mathematical bits and pieces. It is NOT a textbook and doesn't explain everything it introduces; in fact it explains very little. But that is actually what I like best about it. It leaves you wondering about all the different topics and wanting to find out more.

I've been reading The Number Devil, one chapter at a time, to my 4th grade son who is just a little tired of textbook math right now, so this is our little diversion to keep it interesting. Tedious factoring becomes much more palatable when you have already heard a tiny bit about primes and squares!

An engaging story which young readers can identify with - a boy who does not like maths and who does not do very well in the class, whose dreams are taken over by a 'number devil'. The number devil teaches the boy about functions like 'rootabagas' and 'vroom!' in ways which a layman can understand, and how they can be used in the real world - for example, having to shake hands with everyone in a room. Disguised by the odd words in the story, the functions which are taught and explained just seemed like an extravagant attempt at a good story, but as I found out at the end of the book, those strange words are actual mathematical functions, just re-named. 'Vroom!' is factorial, 'rootabagas' are square roots.

I read this book when I was around 12 years old, and did not cover most of the content from the book until years later in school. Making the connection between the story and classroom maths gave me a great advantage when it came to learning the new functions at school (my mind was blown) and I would recommend it to any youngster willing to read.

In the Number Devil Hans Magnus Enzensberger (author) creates a mathematical adventure in a fun way. He names prime numbers prima donna number and shows cool tricks using numbers. In the Number Devil a boy named Robert has dreams each night of the Number Devil. The Number Devil comes into his dreams and teaches him new things about math each night. I myself learned things about math that I didn't know before. If you're looking for a fun mathematical adventure nothing beats this one.

In a children's book reminiscent of The Phantom Tollbooth, the reader is taken along on a magical journey of mathematical discovery. Robert is a twelve-year-old boy who detests math, mainly because his math teacher, Mr. Bockel, is incredibly boring. To the rescue comes the Number Devil, a creature who visits Robert in a series of twelve dreams. During each dream the Number Devil explains different mathematical mysteries and reveals the beauty and simplicity of numbers. In the end, both Robert and the reader gain a new appreciation for math.

I read this book while on holiday visiting a friend overseas. It was left at his house by his 10-year old nephew who hates to read but had actually read (and enjoyed) this book over the summer. I can see why! It was a completely engrossing and fun book. And it made learning math fun! It was a great brush up for me, but I would mostly recommend it for any child, especially fourth, fifth, and sixth graders. This book should be required reading in every elementary school across the country!

This book really helps for children and even for adults too! This book is fun and interesting and not the type of "yellow pages and small writing" type of book. Sometimes when ur teacher teach u sumthing outside the school syllabus, u might not fully understand. BUT, this book makes u understand the whole situaation of waat ur teacher's saying. E.g ur teacher might say sumthi like prime numbers, but in this book the number devil ( a character ) calls it prima donnas!Its really fun! This book is actually teaching u math, but in a story way!

For one who has been volunteer tutoring math to local prisoners seeking to reach GED-level achievment, I think this book has some wonderfully stimulating concepts presented in a refreshing way. I question somewhat the 9-12 year reading level--I might extend that from 12 to "any age." I found the author's truncating of Fibonacci's name to "Bonacci" numbers a little offputting--any kid who can handle these ideas can also deal with the full name of that fascinating sequence. Likewise his replaceing the word "factorial" with "vroom" seems unnecessary, but most likely he was looking for more ways to make things seem "cool." But overall, it's a most engaging and, I should think, stimulating book for the kid of whatever age who can be turned on by the magic of numbers and the concepts behind them.

I was sitting in the school library while my teacher was reading another book.I was daydreaming and then spotted The Number Devil book.
The title seemed interesting so I checked it out. I started reading it and it became very fascinating so I kept on reading.
My interest in Math has increased since reading this book.
I really liked it and couldn't put it down.

I purchased this book at a college book store. I think it was there because it was required reading for math education majors. It also might have been a book for elementary teachers that were taking a math methods course. Regardless of why it was there, I purchased it and read it. It was a fun and interesting look at lots of different math topics.

My son has enjoyed this book since he was about 9 years old. He has probably read it cover to cover at least 5 times and recommends it to all of his friends that like math as much as he does.

You really can't beat it for the price! It's perfect for pre-teens that love math.

For one who has been volunteer tutoring math to local prisoners seeking to reach GED-level achievment, I think this book has some wonderfully stimulating concepts presented in a refreshing way. I question somewhat the 9-12 year reading level--I might extend that from 12 to "any age." I found the author's truncating of Fibonacci's name to "Bonacci" numbers a little offputting--any kid who can handle these ideas can also deal with the full name of that fascinating sequence. Likewise his replaceing the word "factorial" with "vroom" seems unnecessary, but most likely he was looking for more ways to make things seem "cool." But overall, it's a most engaging and, I should think, stimulating book for the kid of whatever age who can be turned on by the magic of numbers and the concepts behind them.

I was sitting in the school library while my teacher was reading another book.I was daydreaming and then spotted The Number Devil book.
The title seemed interesting so I checked it out. I started reading it and it became very fascinating so I kept on reading.
My interest in Math has increased since reading this book.
I really liked it and couldn't put it down.

I purchased this book at a college book store. I think it was there because it was required reading for math education majors. It also might have been a book for elementary teachers that were taking a math methods course. Regardless of why it was there, I purchased it and read it. It was a fun and interesting look at lots of different math topics.

My son has enjoyed this book since he was about 9 years old. He has probably read it cover to cover at least 5 times and recommends it to all of his friends that like math as much as he does.

You really can't beat it for the price! It's perfect for pre-teens that love math.

This book is awesome for learning some cool and hard math concepts! I'm 11 years old and I think this book is a must read. I do recommend that if you're a kid, you should read it with one of your parents. But again, wonderful book, extraordinary illustrations and impressive effort on explaining the complex concepts. I'll rate it five stars! Awesome job, Hans Magnus Enzensberger!

At first our class thought the book would be boring, but we began to look forward to reading about the Number Devil and his new adventures with Robert. If you like fantasy books, you will enjoy this one. The Number Devil is funny, magical, and moody, and once you start reading you'll be hooked on him.

I loved THE NUMBER DEVIL! I've always thught that math was really interesting and exiting, but this book made me even more sure.
THE NUMBER DEVIL is about a boy named robert who starts to dream about a number devil. In his dreams the number devil teaches him all sorts of interesting facts and shortcuts to math problems in an interesting and funny way.
I would have read THE NUMBER DEVIL in about 2 days, but some of the things explained in the book were confusing, so it took alot longer. One thing about the square rute, or rutabaga, of 2 was really confusing and I had to read it about 10 times before it made sense, and there are some things that I still dont get. One thing I thought was weird was I always had to flip back and re-read some of the facts for other things to make sense. Though I have alot of complaints, I like math, and still really enjoyed this book, and would reccomend it to anyone who likes math, or hasn't figured out whats so interesting about it.

The Number Devil is a wonderful adventure about a boy named Robert who was having a hard time in math, and didn't like it at all. I loved all the diffrent math tricks that The Number Devil taught Robert, and how they even found ways to add a little english here and there. If I knew someone that was having a hard time in math, I would refer The Number Devil every time.
Dakista

Whimsical and entertaining, this book actually does make math fun. I first read it when I was eleven, and it opened up a whole new world to me. Rereading it as an adult, I found it every bit as rewarding. There's a surprise on every page. If you happen to be a teacher, don't take the portrayal of Mr. Bockel too personally--this would be a great read for your class.

The Number Devil is an excellent book for all ages. Whether you are bedeviled or bedazzled by math, all readers will love this book. Enzensberger definitely succeeds at seducing even the most frustrated of pupils who aren't particularly fond of math (that would include me). This clever writer charms readers into thinking that numbers aren't little devils afterall.

Number Devil was a fasinating book which captivated my grandsons as we worked through each chapter. Not only were the stories logical, they really maximized the math learning process. Both grandsons, aged 7 and 10, would ask to do another chapter each day.

Very charming. I hated math and I still do ;) but this book got me a little more interested. my twelve year old read it over the summer and loved it. he went on and on about the patterns and persuaded me to read it. This book is excellent or kids and adults.

My 6th grade math-hating students, the students who struggle with math and have little number sense, love hearing this book while drawing reflections and using calculators to crunch the numbers. They are starting to look at numbers in a new way.

THE NUMBER DEVIL WAS A VERY INTERESTING BOOK,IT HELPED ME IN MATH A LOT.AT THE FIRST BEGING OF THE BOOK I DID NOT AT ALL LIKE THE BOOK. IN THE BOOK THEY ALSO TAUGHT ME LANGUAGE.I THINK I WILL GET A VERY GOOD GRADE ON THE BOOK. By.MARKEL

I read this book as a result of coworkers telling me how great it was. To be honest I was not all that impressed. I am a middle school math teacher and have seen all of the "tricks" to solving problems. The problem is that the book doesn't give the reader a strong foundation of number sense as to why these "tricks" work. I felt like I was just reading a Cliff's Notes book to math. I truly was not impressed.