“Inspiring and informative…deserves to be widely read.”
—Wall Street Journal

“This fun book offers a philosophical take on number systems and revels in the beauty of math.”
—Science News

Because we have ten fingers, grouping by ten seems natural, but twelve would be better for divisibility, and eight is well suited to repeated halving. Grouping by two, as in binary code, has turned out to have its own remarkable advantages.

Paul Lockhart presents arithmetic not as rote manipulation of numbers—a practical if mundane branch of knowledge best suited for filling out tax forms—but as a fascinating, sometimes surprising intellectual craft that arises from our desire to add, divide, and multiply important things. Passionate and entertaining, Arithmetic invites us to experience the beauty of mathematics through the eyes of a beguiling teacher.

“A nuanced understanding of working with numbers, gently connecting procedures that we once learned by rote with intuitions long since muddled by education…Lockhart presents arithmetic as a pleasurable pastime, and describes it as a craft like knitting.”
—Jonathon Keats, New Scientist

“What are numbers, how did they arise, why did our ancestors invent them, and how did they represent them? They are, after all, one of humankind’s most brilliant inventions, arguably having greater impact on our lives than the wheel. Lockhart recounts their fascinating story…A wonderful book.”
—Keith Devlin, author of Finding Fibonacci

"Once I started reading, the text proved mind-blowing. Some of the most ingrained and fundamental assumptions about the way we count and understand numbers are here deconstructed and shown to be arbitrary… For the mathematical layman, this book will be a very pleasant surprise… I am delighted to say that Lockhart is a fabulously entertaining writer, and that his light-hearted approach managed to keep me cheerfully engaged even when his discussions were most abstract… It’s in equal measures entertaining and educational, and a pleasant surprise on more levels than one." - PopMatters

"Arithmetic is inspiring and informative, and deserves to be widely read." - Wall Street Journal

"Beginning with counting and moving through topics such as multiplication and fractions, Arithmetic provides a nuanced understanding of working with numbers, gently connecting procedures that we once learned by rote with intuitions long since muddled by education…Lockhart presents arithmetic as a pleasurable pastime, and describes it as a craft like knitting. Manipulating calculi on a tabula, you can see what he means." - New Scientist

"More than just an informative survey of the fundamentals of basic arithmetic, this fun book offers a philosophical take on number systems and revels in the beauty of math." - Science News