What do you think?
Rate this book
Unequal: The Math of When Things Do and Don't Add Up
Why the familiar equal sign is a gateway into math’s—and humanity’s—most profound questions
"Eugenia Cheng has opened up my mind to the wondrous world of pure mathematics in a way that I never thought was possible."―Willow Smith, singer and actress
A New Scientist Best Book of the Year
Math is famous for its 1 + 1 = 2, a^2 + b^2 = c^2, or y = mx + b. It can seem like that’s all mathematics following steps to show that what’s on one side of an equation is the same as what’s on the other.
In Unequal, Eugenia Cheng shows that’s just part of the story, and the boring part to boot. Mathematics is a world of shapes, symmetries, and logical ideas. And in that world, the boundary between things being equal and unequal is a gray area, or perhaps a rainbow of beautiful, vibrant, subtly nuanced color.
As Unequal shows, once you go over that rainbow, almost everything can be considered equal and unequal at the same time, whether it’s shapes (seen from the right perspective, a circle is the same as an ellipse), words (synonyms), or people—even numbers! That’s because mathematics isn’t a series of rules, facts, or answers. It’s an invitation to a more powerful way of thinking.
"Eugenia Cheng has opened up my mind to the wondrous world of pure mathematics in a way that I never thought was possible."―Willow Smith, singer and actress
A New Scientist Best Book of the Year
Math is famous for its 1 + 1 = 2, a^2 + b^2 = c^2, or y = mx + b. It can seem like that’s all mathematics following steps to show that what’s on one side of an equation is the same as what’s on the other.
In Unequal, Eugenia Cheng shows that’s just part of the story, and the boring part to boot. Mathematics is a world of shapes, symmetries, and logical ideas. And in that world, the boundary between things being equal and unequal is a gray area, or perhaps a rainbow of beautiful, vibrant, subtly nuanced color.
As Unequal shows, once you go over that rainbow, almost everything can be considered equal and unequal at the same time, whether it’s shapes (seen from the right perspective, a circle is the same as an ellipse), words (synonyms), or people—even numbers! That’s because mathematics isn’t a series of rules, facts, or answers. It’s an invitation to a more powerful way of thinking.
401 pages, Kindle Edition
Published September 2, 2025
18 people are currently reading
1 person want to read
About the author
Eugenia Cheng
17 books346 followersEugenia Cheng is a mathematician, pianist, and lecturer. She is passionate about ridding the world of math-phobia. Eugenia’s first book, How to Bake Pi, has been an international success. Molly’s Mathematical Adventure is her first children's book.
Ratings & Reviews
Friends & Following
Create a free account to discover what your friends think of this book!
Community Reviews
No one has reviewed this book yet.