**The Number Devil: A Mathematical Adventure **

by Hans Magnus Enzensberger, Rotraut Susanne Berner (Illustrator), Michael Henry Heim (Translator)

The Number Devil: A Mathematical Adventure

Young Robert’s dreams have taken a decided turn for the weird. Instead of falling down holes and such, he’s visiting a bizarre magical land of number tricks with the number devil as his host. Starting at one and adding zero and all the rest of the numbers, Robert and the number devil use giant furry calculators, piles of coconuts, and endlessly scrolling paper to introduce …more Young Robert’s dreams have taken a decided turn for the weird. Instead of falling down holes and such, he’s visiting a bizarre magical land of number tricks with the number devil as his host. Starting at one and adding zero and all the rest of the numbers, Robert and the number devil use giant furry calculators, piles of coconuts, and endlessly scrolling paper to introduce basic concepts of numeracy, from interesting number sequences to exponents to matrices. Author Hans Magnus Enzensberger’s dry humor and sense of wonder will keep you and your kids entranced while you learn (shhh!) mathematical principles. Who could resist the little red guy who calls prime numbers “prima donnas,” irrational numbers “unreasonable,” and roots “rutabagas”? Not that the number devil is without his devilish qualities. He loses his temper when Robert looks for the easy way out of a number puzzle or dismisses math as boring and useless. “What do you expect?” he asks. “I’m the number devil, not Santa Claus.” (Ages 10 to adult) *–Therese Littleton*

Beth of goodreads summarizes this book very nicely. She writes:

What do you get when you cross Alice in Wonderland with a small, red, horned man obsessed with numbers? No, it isn’t an arithmetic problem – it’s a middle school math primer!

Robert, a boy who hates math and is frustrated because his teacher doesn’t allow calculators, has strange dreams all the time. One night he dreams up a character called the Number Devil, who takes him away to a surreal world of numbers where Robert learns basic math concepts and a few handy shortcuts. After all, says the Number Devil, “you learn best when you sleep.”

Over the course of 12 different evenings, Robert learns factorials, how to find a square root, and more. Concepts such as the importance of the number zero and the idea of infinity are stressed over and over. Robert discovers triangle number, Bonacci numbers, imaginary numbers, and irrational numbers. Did you know that you can take any even number larger than two and find 2 prime number that add up to it? Robert is even able to apply what he’s learned in an actual math class.

The Number Devil makes up fun – and punny – terms for things. Roots become “rutabagas” (a root vegetable) and prime numbers are “prima donnas.” Squaring becomes “number hopping,” and factorials (!) are renamed “vrooms.” A warning at the end reminds kids to use the proper terms in class. The index doubles as a brief glossary, defining terms in a few words.

It is truly remarkable how clearly the theories are presented. Enzensberger translates math to German, and Berner translates the German to English. The concepts are well explained and provide jumping off points for many discussions, from pyramids to mosaics to biographies of mathematicians. Whimsical illustrations and colorful charts and diagrams add to the text. Practical applications relate to nature in many cases. Bonacci numbers are illustrated with rapidly multiplying bunny rabbits. Similar examples would have been great! Related activities include playing with number triangles and making 3-D geometric shapes. There are no pages of practice problems or exercises, although one or two chapters end with a question for a student to solve by extrapolating new information.

Middle school teachers can spice up their lectures with a chapter from this book. Homeschoolers can use it as a unique supplemental text. While some might object to the negative imagery surrounding math (Robert is in number hell, and learns from a devil), the book may reach some kids who relate to the main character. This math-phobic librarian (the only numbers I’m good at are Dewey Decimal ones). Can’t wait for the sequel!

As our school focus this year is to implement more H.O.T.S. (Higher Order Thinking Skills) Activities I am excited to begin having my class study this novel. I was fortunate to have the opportunity at the recent MCATA Conference held in Calgary, to attend a session presented by Karen J Cleveland. I intend to explore this book with my grade five class this next term.

Following are links to some websites that I found. They contain lesson activities to use chapter by chapter as you study The Number Devil.

http://projects.cbe.ab.ca/glendale/showcase/numberdevil/index.html

http://moreofamom.com/2009/02/05/number-devil-activities-the-third-night/

http://mindflight.plymouth.edu/icet/2002/icet2002/projects/kearsarge/04_night.html

I’m hoping my text books will arrive this Monday, and my class can begin this new journey! I will keep you posted!