The Big Book of Pi: The Famous Number You Can Never Know by Jean-Baptiste Aubin and Anita Lehmann

What worked:

All middle-grade readers have heard of Pi, but the only thing they probably know is that it equals 3.14. This book takes readers back to the creation of the concept and describes its evolution over the years. Why is it called Pi and not something else? Mathematicians throughout history have tried to understand Pi and calculate its value as exactly as possible. The fact that its value is infinite and non-repeating means no one can ever find an exact number. The book shares different strategies used by ancient Egyptians and Babylonians, Archimedes, and other people around the world. Some pages apply the concept to calculate values related to curved objects and solve mathematical questions.

The book is loaded with colorful illustrations and diagrams to help readers understand Pi. The diagrams are helpful when explaining strategies and applying them to solve problems. Definitions of mathematical terms are found at the bottom of the pages where they’re used and at the back of the book. “Fun facts” and other interesting information can also be found at the bottom of some pages. Did you know Pi Day is celebrated on March 14 (3/14)? A couple of pages share a Pi-related “magic” trick and Pi-related jokes. The official creatures of Pi Day are octopi.

What didn’t work as well:

Describing the methods people used to calculate the value of Pi becomes redundant. It’s interesting, but there’s a limit to the attention span of young readers. A redeeming factor is that the authors have a sense of humor, so the narrative is light-hearted and fun.

The final verdict:

This book is most appropriate for upper middle-grade readers. It won’t appeal to the general audience, but I recommend it to readers with a love for math. Dare I say math nerds?