# Guesstimation: Solving the World's Problems on the Back of a Cocktail Napkin

## Synopsis

Guesstimation is a book that unlocks the power of approximation--it's popular mathematics rounded to the nearest power of ten! The ability to estimate is an important skill in daily life. More and more leading businesses today use estimation questions in interviews to test applicants' abilities to think on their feet. Guesstimation enables anyone with basic math and science skills to estimate virtually anything--quickly--using plausible assumptions and elementary arithmetic.

Lawrence Weinstein and John Adam present an eclectic array of estimation problems that range from devilishly simple to quite sophisticated and from serious real-world concerns to downright silly ones. How long would it take a running faucet to fill the inverted dome of the Capitol? What is the total length of all the pickles consumed in the US in one year? What are the relative merits of internal-combustion and electric cars, of coal and nuclear energy? The problems are marvelously diverse, yet the skills to solve them are the same. The authors show how easy it is to derive useful ballpark estimates by breaking complex problems into simpler, more manageable ones--and how there can be many paths to the right answer. The book is written in a question-and-answer format with lots of hints along the way. It includes a handy appendix summarizing the few formulas and basic science concepts needed, and its small size and French-fold design make it conveniently portable. Illustrated with humorous pen-and-ink sketches, Guesstimation will delight popular-math enthusiasts and is ideal for the classroom.

## Excerpt

How big is it?

Numbers are thrown at us all the time. They are frequently used to scare us: “Shark attacks doubled this year!” or “Dozens of lives could be saved by using infant car seats on airplanes!” They are often used to tempt us: “This week's lottery prize is \$100 million!” They are certainly needed to understand the world around us: “The average American produces 100 cubic feet of garbage every year!” or “Nuclear power plants produce tons of high-level radioactive waste!”

You can make sense of these often confusing and sometimes contradictory numbers with just two tools: (1) an understanding of the meaning of large numbers and (2) an ability to make rough, common-sense, estimates starting from just a few basic facts. We'll teach you these straightforward skills so you can better understand the world around you and better recognize numerical, political, and scientific nonsense.

You can also use these tools to further your career. Many top companies use estimation questions in job interviews to judge the intelligence and flexibility of their applicants [1]. Leading software firms, management consultants, and investment banks (for example, Microsoft, Goldman Sachs, and Smith Barney) ask questions such as What's the size of the market for disposable diapers in China? Howmany golf balls does it take to fill a 747? and How many piano tuners are there in the world? [2, 3] Companies use these questions as an excellent test of the applicants' abilities to think on their feet and to apply their mathematical skills to real-world problems.

These problems are frequently called “Fermi problems,” after the legendary physicist Enrico Fermi, who . . .

Search by...
Show...

### Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.