The Number Devil: A Mathematical Adventure

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Hans Magnus Enzensberger is the author of many highly lauded books, including Civil Wars: From L.A. to Bosnia. He lives in Munich.

The Number Devil by Hans Magnus Enzensberger - Waterstones The Number Devil by Hans Magnus Enzensberger - Waterstones

This is the summer reading book for our incoming 8th graders. Writing Across the Curriculum is a key component of our PreK-12 school. The 8th grade teachers have developed activities to go with many of the chapters. We have the students work in groups throughout the school year on these and then each student is required to write an essay or creative story to explain how they found (or tried to find) the answers to the questions posed. We start off with the students finding out about the pattern with the multiplication of ones (1x1, 11x11, 111x111, etc.), then go on to exploring the "Prima Donnas", terminating and repeating decimals, square numbers, geometric patterns in Pascal's Triangle along with its relationship with the binomial expansion and also permutations and combinations, and summation. As our "last chapter", the students pretend they are a Number Devil and research a topic to explain to someone as their first assignment as a number devil. It's a great book because it is easy to read and gets kids to think about mathematical ideas. It can be read by people of many ages. I read it to my children as 3rd and 5th graders when we were driving to Nova Scotia. My son then read it again for a project when he was in 5th grade. I would love to have a sequel! Suppose I have invited 20 guests to a party but only have enough seating for 10. How many different possibilities are there for the list of 10 people who get to sit? It would take too long to try to list all possible choices of 10 names of the 20 guests. Instead, we should use the triangle. The number of possible sets of 10 selected out of a larger set of 20 would be the number in the 10th spot in the 20th row of Pascal's Triangle: 184756. I really loved this book, and as a future math educator, I found it to be very useful for something I could one day use in the classroom. The only thing that bothers me is that they use fake and "quirky" names for the mathematical concepts. It was ok for me, because I know what they are actually called; however, if a student was reading the book for themselves, they may have issues translating those ideas when they see them in class. I really wish that the book would have just put the actual names of the concepts, and not tried to be as cute. I did really like the way the concepts were presented and thought it was a great way to get kids interested in math. The Number Devil was a great book. I had to read it for a project in math and found it more than enjoyable. Some of the math concepts were a little confusing but managable.Another type of question that is answered by Pascal's Triangle has to do with algebra. Most algebra students know that (x+y) 2=x 2+2xy+y 2. Note that the coefficients in this expansion are the same as the numbers in the second row of the triangle! More generally, you can read off the coefficients of (x+y) n from the nth row of the table. The fourth row is "1 4 6 4 1" which means that (x+y) 4=x Adults who know a little about math will find this book as enlightening as younger readers will." -- Martin Gardner, Los Angeles Times

666 (number) - Wikipedia 666 (number) - Wikipedia

This is a really fun way for kids, well anyone really, to read about math. I read it for a college course in a secondary education program (although I am English and not Math), and am currently working with a group to create an interdisciplinary unit centered around this book. It's challenging, but we're finding some really fun ways to create 3-week units for 3 different subjects: English, Math, and Art. And there are many others that behave even worse, that go off the deep end after their zero. They are called the unreasonable numbers, and the reason they're called that is that they refuse to play by the rules. In the case of the ratios of Fibonacci terms, Robert is looking at a list and notes that 89/55 has a repeating 18 in its decimal expansion, but describes 21/13 as "looking as unreasonable as they come". Of course, 21/13 is not irrational, and perhaps Robert should know that, too. However, he doesn't actually say it is unreasonable, only that the decimal expansion looks unreasonable. In other words, this is an example, such as the type I warned about in the previous paragraph, which might look irrational on a calculator since the repeating pattern is not apparent. The author further confuses things by pointing out that the limit as n goes to infinity of the ratio of the n and n+1 term in the sequence actually is an irrational (unreasonable) number. I will agree that this may muddle things to the point that someone who is naive about number theory would become confused. However, looking at it myself now, I cannot see that he ever says anything that is actually wrong. I'm a 6th grader and i just love to read this book for fun!! it was hidden away for a few years and when i remembered it again, itook it off the shelf again. 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.This book is a wonderfully funny way to talk about math. My 8 yr. old daughter is thrilled about reading the next "night/chapter", even though some of the math concepts are way beyond her level. It's an excellent book!! This is without doubt one of the best mathematical fictions I've read. I frequently re-read it just for fun, and every so often, I'll get into a conversation about it with one of my "geeky" friends. 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. However, I have to say that the number devil is a little on the sarcastic side which, if he was a real person, would turn off a mathophobic middle-schooler. Overall, my husband, who's not fond of math, thought it was a fun math reading he thought he missed out on growing up. I have recommended this to many of my homeschool friends.

The Number Devil by Hans Magnus Enzensberger - Waterstones

My fourth grade daughter and I alternated reading a chapter aloud every day. It was a funny and interesting book that made my math phobic daughter think of math in a friendlier way. I don't think she LOVES math...yet, but at least she doesn't hate it so badly. I'm sure we'll read it again. I am in seventh grade. We read this book to learn and have fun. I had never imagined what had awaited me !(vroom) I do have a question about the concepts covered in the book. Are the concepts such as Fibonacci numbers and Pascal's triangle merely mathematical "recreations" or are they actually useful for something? My question is about irrational numbers ( "unreasonable numbers" as they are called in the book). In the index of the book, "unreasonable numbers" are translated as irrational. I think there is a problem here! Though I found the math, explanations and diagrams mathematically sound, I did not find the definition of irrational numbers sound. In chapter 4, didn't the author define the fractions 7/11 and 6/7 as irrational, when they are really rational? In chapter 10, are not all the quotients of the neighboring terms of the Fibonnaci Series rational? He defined them as irrational.

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.

666 Meaning - Is This Number Evil Or Just Misunderstood? 666 Meaning - Is This Number Evil Or Just Misunderstood?

No, I don't think he has actually said anything wrong. Perhaps he has not been careful enough to make his point clear, but if you read closely you can see that he never makes the mistake of calling a rational number "unreasonable". There are in fact many applications for Pascal's Triangle, because the numbers in its rows are the answers to two very practical types of questions. Before I get to that, however, I need to set up a sort of strange terminology. Let's say that the top of the triangle ("1") is the 0th row and that the next row ("1 1") is the 1st row and the next row ("1 2 1") is the second row and so on...since that will make it easier for me to explain. And similarly, let's call the 1 at the start of each row the "zeroeth" number in that row and the number after it the first number. So, according to this strange notation, the first number in the second row is 2...right? Okay. Now, I can show you an application of the triangle.He goes on to suggest that Robert take the square root ("rutabaga") of 2 and notes that he does not see any repeats in the decimal expansion. Now, one could argue that this is not a valid proof that the square root of 2 is irrational, since it could possibly just have a repeating pattern that is not apparent in the display of Robert's calculator (just as it is possible that the apparent pattern of 7/11 breaks down somewhere outside of the display on his calculator). But, he does not say that 7/11 or 6/7 are unreasonable...he is trying to draw a contrast between those rational numbers and the irrational square root of 2. My 5 and 7 year old kids love THe Number Devil, they would beg me to read it some more to them. Although some of the concepts may be a bit too deep for my 5 year old daughter but the way the concepts are presented in a playful way where kids can relate to is excellent.