Book Recommendations 好書推薦

The Number Devil

A mathematical adventure
​by Hans Magnus Enzensberger

Recommended reading age: 10-13 years
Lexile measure: 580

An imaginative, quick-paced novel, The Number Devil follows the dreams of twelve-year-old Robert as he encounters the “number devil” — a fictional creature determined to infuse the young boy with a passion for maths. Robert is teleported in his dreams to various landscapes that visualize a range of mathematical concepts from prime numbers to perfect squares, accompanied by the enthusiastic yet short-tempered devil. In this way, German writer Hans Magnus Enzensberger conveys the fundamentals of algebra and numerical thinking through an engaging storyline and vivid characters that children will immediately laugh at and love.

Why we recommended

The Number Devil is a fantastic way to expose young readers to the exciting aspects of maths. With colorful diagrams and illustrations accompanying the fast-paced dialogue and the number devil’s explanations, the novel rejects the idea of maths as a rote, calculation-based subject. Instead, Enzensberger approaches it from a fresh and playful perspective. He focuses on fascinating concepts such as irrational numbers, the importance of zero, Pascal’s triangle, the Fibonacci series and even combinatorics — a valuable preparation for young readers who will soon be taught these concepts in the classroom.
The writer successfully breaks down complex mathematical ideas into visual, engaging, story-based adventures: for example, explaining the concept of different infinities by marching long lines of imaginary people into Robert’s bedroom. Children can even take part in Robert’s journey and follow along his calculations — the book includes several activities for readers as well. As Enzensberger traces the young boy’s journey from hating the subject to relishing his nightly mathematical expeditions, young readers’ perception of maths will also be transformed as they fall in love with the book’s characters, and at the same time, with the wonder of maths.

Post-reading Questions & activities 

(adapted from NZ maths):

1. Second night: What do you think would happen to the world without zero?
2. Fifth night: Only two numbers between 1 and 100 are both square numbers and triangle numbers. The first is the number 1. Can you find the other?
3. Sixth night: Research who Fibonacci was. What examples of the Fibonacci series exist in nature?
4. Ninth night: How would you explain what infinity is in your own words?

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The article is written by Noa Shmueli
About Noa
Graduated from Taipei European School, Noa is now majoring in English at Columbia University and Trinity College Dublin. An avid reader and writer, she was the Editor-in-Chief of the TES student magazine, PEAK, and have been editing textbooks and essays since 2016.