I was expecting a book that was more calculator focussed, perhaps misled by the sub-title. This is a book about pocket (and other) calculators, but it’s more a book about calculation and its mechanical assistants, from the abacus and Napier’s Bones through to computers.

And that having been said, it’s a great history. It addresses the needs that have driven mechanical computation over the centuries, as the applications have changed alongside the technology (and in many ways have driven its development). You can see this in the way that the scale of the machines changes, becoming alternately smaller and more pocket-sized and then larger as the increasing demands require steam or electrical power. (The latter can be miniaturised while the former clearly can’t.)

What we would actually regard as pocket calculators occupy only a tiny part of the story. I think there’s a more detailed history that could still be written about the different processors used, methods of entry used (for example HP’s determined and continued use of reverse-Polish notation), and how these were taken up by sub-groups within science, engineering, and finance and used almost as tribal signifiers (“real engineers use HP”). But that would miss the wider story that this book tells well.

4/5. Finished Monday 9 June, 2025.

(Originally published on Goodreads.)