Robin Hood Math: Take Control of the Algorithms That Run Your Life

by Noah Giansiracusa

How the rich and powerful use math to exploit you, and what you can do to beat them at their own game

    Everything we do today is recorded as data that's sold to the highest bidder. Plugging our personal data into impersonal algorithms has made government agencies more efficient and tech companies more profitable. But all this comes at a price. It's easy to feel like an insignificant number in a world of number crunchers who care more about their bottom line than your humanity. It's time to flip the equation, turning math into an empowering tool for the rest of us.

    Award-winning mathematician Noah Giansiracusa explains how the tech giants and financial institutions use formulas to get ahead—and how anyone can use these same formulas in their everyday life. You’ll learn how to handle risk rationally, make better investments, take control of your social media, and reclaim agency over the decisions you make each day. 

    In a society that all too often takes from the poor and gives to the rich, math can be a vital democratizing force. Robin Hood Math helps you to think for yourself, act in your own best interests, and thrive.

Genres: Nonfiction, Mathematics

244 pages, Kindle Edition

Published August 5, 2025

Reviews

[Annahita · Rating 4 out of 5]

Thank you to Riverhead Books for the #gifted finished copy of Robin Hood Math by Noah Giansiracusa, publishing August 5!

As a words person (hi, comms-nerd here!), I’ve never naturally gravitated toward numbers. But this one caught my eye as a way to stretch myself, and I’m so glad I picked it up.

Robin Hood Math is a smart, surprisingly approachable read about how formulas shape the world around us, from investments and insurance to social media and personal decision-making. Giansiracusa breaks down how the rich and powerful use math and algorithms to tilt the playing field in their favor, and how the rest of us can flip the equation and take back some control.

I found it super engaging, eye-opening, and far from dry. Whether he’s walking through the logic of rational risk or explaining how data is bought and sold, Giansiracusa makes the numbers feel empowering, not overwhelming.

This is a great read for anyone curious about how to navigate our algorithm-driven world with more agency and intention. Highly recommend!

[Scott Ward · Rating 5 out of 5]

What a fun and helpful read! If you’ve paid attention to many of the social media and online search/buying scandals, you’ll be familiar with what Giansiracusa details in this book. If you’ve thought about better ways to spend time on (or avoid) social media apps, many of the recommendations will feel like common sense to you. But you will learn more about how to shop better, scroll better and be less anxious by what’s being “fed” to you because of some choices and actions you’ve made. Similarly, you’ll learn more about finances and how to interpret other people’s analyses—and do your own perhaps to calm some medical scares. Polling may make sense. Risk assessments will make more sense. And the author teaches you how to do a lot of this on your own if you want.

Very helpful suggestions in each chapter come after example stories and a breakdown of what’s happening “behind the scenes.” While the stories are illustrative, many are long—which you can skim if you want to accelerate to the gist of the chapters—and some concepts/points in the argument are repetitive. The repetition isn’t all bad as most of us need repetition for lessons to sink in.

While this book describes the state of the art “today,” tech-related scenarios will change as companies continue to adapt their algorithms to altered priorities and regulations. This book, however, will give you some ways to look for the changes, take stock of the changes and adapt your usages and decision-making as well.

I’m appreciative of the publisher providing an advanced copy.

[Julie]

This isn’t the book I expected based on the blurb and marketing. It is, in short, a book on real-world applied mathematics, such as using weighted sums to prepare your own personalized rankings for things you care about, or using Bayesian reasoning to figure out how certain you should be of your opinions. The last couple of chapters deal with social media and other online algorithms ¬– what I expected the bulk of the book would be about when I picked it up – but I found the solutions he gives to be somewhat milquetoast. When it comes to social media, he recommends “engage with content you want to see more of, and don’t engage with content you don’t want to see more of.” Y’know, the sort of recommendation that anyone who’s done even a cursory search into social media algorithms would be able to figure out. With the enshittification of the internet more broadly, he recommends collective action, specifically a tax on personalized ads. To which I say: great idea, and more power to him in ever getting something like that passed. It’s not that I thought this book was bad – it was fine for what it was – I was just expecting more from it than I got.

[Shaun W · Rating 4 out of 5]

The math is pretty simple with weighted sums/ averages, some predictions and beyes with decent examples including how social media ranking methods.

Didn’t need the last chapter on progressive tax recommendations 🤷‍♂️ but overall a good and very easy read.