# Guesstimation (Lawrence Weinstein, John Adam)

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.

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The conversion efficiency (the ratio of animal feed to animal weight) varies from two for chickens and fish through four for pork to seven for beef.

## 2 thoughts on “Guesstimation (Lawrence Weinstein, John Adam)”

1. shinichi Post author

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

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.

2. shinichi Post author

# Guesstimate

Wikipedia

https://en.wikipedia.org/wiki/Guesstimate

Guesstimate is an informal English portmanteau of guess and estimate, first used by American statisticians in 1934 or 1935. It is defined as an estimate made without using adequate or complete information, or, more strongly, as an estimate arrived at by guesswork or conjecture. Like the words estimate and guess, guesstimate may be used as a verb or a noun (with the same change in pronunciation as estimate). A guesstimate may be a first rough approximation pending a more accurate estimate, or it may be an educated guess at something for which no better information will become available.

The word may be used in a pejorative sense if information for a better estimate is available but ignored.

Guesstimation techniques are used:

• in physics, where the use of guesstimation techniques to solve Fermi problems is taught as a useful skill to science students;
• in cosmology, where the Drake equation is a well-known guesstimation method;
• in economics, where economic forecasts and statistics are often based on guesstimates; and
• in software engineering, where new development of features and release timelines are based on effort guesstimates of tasks.

Lawrence Weinstein and John Adam’s 2009 book Guesstimation: Solving the World’s Problems on the Back of a Cocktail Napkin, based on the course “Physics on the Back of an Envelope” at Old Dominion University, promotes guesstimation techniques as a useful life skill. It includes many worked examples of guesstimation, including estimating the total number of miles that Americans drive in a year (about 2 trillion) and the amount of high-level nuclear waste that a 1 GW nuclear power plant produces in a year (about 60 tons).