The Penguin Dictionary of Curious and Interesting Numbers (Penguin Press Science)

Why it's worth it

This is a cabinet of numerical curiosities, arranged smallest to largest, that you open at random for ten minutes at a time. If someone in your life lights up about primes or pi, they'll keep it within arm's reach for years.

It's built to be opened at random. Entries run from the small numbers upward, each a short note on why that particular number deserves a second look. You read three, get curious, then read nine more. That's a different pleasure from a narrative book, and for a lot of people it's a more durable one, because the book stays on the desk instead of migrating to a shelf.

The entries are short and reliably surprising. The number 1,729 is the smallest you can write as the sum of two cubes in two different ways. Pi and e get their own strange histories. Mersenne primes, factorization oddities and mathematical folklore all show up. Owners who work with numbers professionally say it still catches them out, which is a decent signal of how deep it goes.

From our review of 5 science books for curious readers, by Genevieve Dubois, Home & Living Expert

What we like

• +It's built to be opened at random
• +The entries are short and reliably surprising
• +Teachers get the most out of it
• +Nothing in it goes out of date

What to know

• –There's no through-line at all
• –Some entries assume you already speak a little math
• –This listing is the digital edition