Delicious book of being read and precious as for the information that are contained in him.
A thought exercise, of reflection, more than a mathematical exercise.
I recommend for all those that appreciate the world in that you live, but that cannot leave of looking it with critic.

If you can do basic arithmetic with one-digit numbers - add, subtract, multiply, divide - you can be a math genius. Maybe not genius, but you can still blow the doors off most people, and build up a healthy amount of BS-proofing, just by learning how to apply the skills you already have. This book offers dozens of worked examples, using pretty much just the math you learned by sixth grade.

Weinstein and Adam chose a format that's easy to pick up and thumb through. They present each poser on one page, with hints to help you get started. A few extra facts "to hang things on" appear at the back of the book: the sun is about 10^11 meters away, a billion seconds is about 30 years, things like that. Then, the next page or two after the problem works out its answer, often more than one way.

For example: could we create a human chain from Earth to the sun? Well, the sun is about 10^11 meters away, and a person is about 10^0 meters from fingertip to fingertip with arms stretched out. (For back-of-the-envelope purposes, you can often skip the leading digits of numbers.) So, the distance from earth to sun is about 10^11 people-widths, but the Earth's human population is just under 10^10. Answer: We'd certainly come up short.

Some questions, like that one, are silly factoids. Others have more pressing social importance. How much funding does a subsidized school lunch program need per year? How many acres of farmland would it take to fuel your car with ethanol? How much landfill area does your town need for the next decade? When political special interests start throwing numbers around to answer these questions, are they lying to you? Even if you don't have exact numbers to work with, the way you get the answer is what matters, and you know exactly what assumptions you've made. Then, when you get more facts, you can refine your answer.

You don't have to be a nerd to command a lot of nerd power. Grade-school arithmetic (which the authors review), a few basic facts, and a bucket of common sense go a long way. This book, with its puzzle-solving format, can help you develop that skill.

-- wiredweird

If you can do basic arithmetic with one-digit numbers - add, subtract, multiply, divide - you can be a math genius. Maybe not genius, but you can still blow the doors off most people, and build up a healthy amount of BS-proofing, just by learning how to apply the skills you already have. This book offers dozens of worked examples, using pretty much just the math you learned by sixth grade.

Weinstein and Adam chose a format that's easy to pick up and thumb through. They present each poser on one page, with hints to help you get started. A few extra facts "to hang things on" appear at the back of the book: the sun is about 10^11 meters away, a billion seconds is about 30 years, things like that. Then, the next page or two after the problem works out its answer, often more than one way.

For example: could we create a human chain from Earth to the sun? Well, the sun is about 10^11 meters away, and a person is about 10^1 meters from fingertip to fingertip with arms stretch out. (For back-of-the-envelope purposes, you can often skip the leading digits of numbers.) So, the distance from earth to sun is about 10^10 people-widths, about the Earth's human population. I underestimated arm's-length and overestimated population, so the two errors cancel, somewhat. If everyone on earth formed a human chain, holding hands, it would be very roughly the right distance. Answer: Maybe, it's not out of the question. I'd have to go into details to get it exact.

Some questions, like that one, are silly factoids. Others have more pressing social importance. How much funding does a subsidized school lunch program need per year? How many acres of farmland would it take to fuel your car with ethanol? How much landfill area does your town need for the next decade? When political special interests start throwing numbers around to answer these questions, are they lying to you? Even if you don't have exact numbers to work with, the way you get the answer is what matters, and you know exactly what assumptions you've made. Then, when you get more facts, you can refine your answer.

You don't have to be a nerd to command a lot of nerd power. Grade-school arithmetic (which the authors review), a few basic facts, and a bucket of common sense go a long way. This book, with its puzzle-solving format, can help you develop that skill.

-- wiredweird

This book was entertaining reading...except that most of the more interesting examples described in this book were so familiar. This is one of those books where I might rate it better if it weren't for the fact that there is a far better book for anyone interested in this topic. Like Guesstimation, How to Measure Anything: Finding the Value of "Intangibles" in Business by Douglas Hubbard also discusses the Fermi approach and how ancient Greeks estimated the circumfrance of the Earth (Hubbard's book uses these same examples even though it came out almost a year before Guesstimation...curious). But Hubbard picks up where Guestimation, as another reviewer puts it, "falls short". After a bit of "Fermi decomposition", Hubbard discusses how we can learn to excel at subjectively assessing odds and ranges and how we can compute the value of further measurement. Then he gets into a fascinating array of practical methods of observation to further reduce uncertainty. Although the techniques in Hubbard's book are based on sophisticated mathematical methods, he is able to reach a much broader audience by distilling the math into simple charts, tables and procedures. In short, if you owned both of these books, Guesstimation would be redundant and wouldn't cover nearly as much.

This book was entertaining reading...except that most of the more interesting examples described in this book were so familiar. This is one of those books where I might rate it better if it weren't for the fact that there is a far better book for anyone interested in this topic. How to Measure Anything: Finding the Value of "Intangibles" in Business by Douglas Hubbard also discusses the Fermi approach and how ancient Greeks estimated the circumfrance of the Earth (Hubbard's book uses these same examples even though it came out almost a year before Guesstimation...curious). But Hubbard picks up where Guestimation, as another reviewer puts it, "falls short". After a bit of "Fermi decomposition", Hubbard discusses how we can learn to excel at subjectively assessing odds and ranges and how we can compute the value of further measurement. Then he gets into a fascinating array of practical methods of observation to further reduce uncertainty. Although the techniques in Hubbard's book are based on sophisticated mathematical methods, he is able to reach a much broader audience by distilling the math into simple charts, tables and procedures. In short, if you owned both of these books, Guesstimation would be redundant and wouldn't cover nearly as much.

This is a great "hands on" book that teaches the art of making a quantitative "educated" guess based on just a few basic facts most people know (or should know). I found this book great reading and very educational. Recommended for anyone.

Somehow, guessing at numbers is unsettling, even though I've done it all my life. John Adam is a professor of applied mathematics, with a degree in physics. Larry Weinstein is a nuclear physicist. Their book is devoted to proving that intelligent guessing is useful and fun.

The book lays out some general principles but its great strength lies in the interesting problems, a series of hints to help you solve each problem, and an interesting discussion of the pitfalls and triumphs involved. Three key points: estimate by powers of ten, break complex problems into simple steps and consider alternative approaches.

The book includes an excellent appendix containing a few formulas and scientific concepts, together with some useful statistics. The pen-and-ink sketches are funny and to the point.

Best of all, the Princeton Press maintains a site with new problems on a weekly basis; a recent question was how many golf balls would it take to encircle the earth at the equator. Hints included:

a. What is the diameter of a golf ball?

b. What is the circumference of the earth?

The authors give several interesting hints at determining the circumference of the earth (if you don't know it), including the 24 time zones, the number of time zones in the US, the time it takes to fly from New York City to Los Angeles, etc.

Brain stretching stuff, which is always good for you, and the publishers claim job applicants should be prepared for tests of their estimating abilities. The Chinese rights have just been sold, and we may face even more competition on that front as well. If you learn by doing, this book is a great way to improve your skills and have fun doing it.

Robert C. Ross 2008

The idea of this book is great, and I had hoped to learn new principles for estimation. Unfortunately, the execution falls short. I expected the authors to teach methods and techniques, but instead they rely almost exclusively on examples that try to teach by illustration. I don't find that style effective and I had hoped for a deeper presentation.