The Number Devil: Youth Review

Posted by on Aug 24, 2021 in Featured Titles, News | No Comments

The following review of Mathical Hall of Fame book The Number Devil by Hans Magnus Enzensberger was submitted by California high school student Madeleine de Belloy.

Hans Magnus Enzensberger brings out the beauty in mathematics in his 1997 book The Number Devil. In a series of twelve dreams, Robert, a young boy persuaded that math can only be a tedious and taxing endeavour, is confronted by a witty, hot-headed number devil who is determined to show him otherwise. This unlikely mentor introduces Robert to the world of prima donna numbers and Bonacci rabbits while seated on giant mushroom armchairs in a forest full of number ones. Each chapter is filled with fun adventures punctuated by surprising number tricks as we follow Robert’s entry into math. 

The Number Devil masterfully leads us through a path of math discovery, starting with the very basics and building up to much more complex observations. On the first couple nights, we begin with the origin of zero and the definition of prime numbers but by the end of the book, Robert is exploring the intricacies of convergent and divergent series and the relationship between dots, lines, and spaces in a graph. By laying down a solid foundation, Enzensberger reflects rigorous mathematical thinking in a light-hearted environment. The Number Devil also does a fantastic job showing off the many patterns hidden within Pascal’s triangle, accompanied by whimsical but very clear pictures, and insists on the cyclical quality of math: that many concepts or patterns crop up again and again. 

Whether you’re discovering these math tricks for the first time or challenging yourself to prove the number devil’s fantastic claims, this trip through Robert’s dreams is a truly worthwhile mathematical adventure.  Although we can’t all meet a number devil, Enzensberger’s book brings us as close as we can get.

The Number Devil
By Hans Magnus Enzensberger
Macmillan Children’s Publishing Group, 1997
Mathical Hall of Fame Book


Madeleine de BelloyMadeleine de Belloy is a Franco-American high school student living in the San Francisco Bay Area. Madeleine loves math, particularly number theory, and is involved in the preparation program for the French Math Olympiad team and Math en Jeans, a math research program. She has both attended and taught at math circles and spends her summers at math camps.