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200% of Nothing
Acclaim for "In today's world, 'innumeracy' is an even greaterdanger than illiteracy, and is perhaps even more common.Advertisers and politicians exploit it; intellectuals (self-styled)even flaunt it. I hope that this wise and witty book will providecures where they are possible, and warnings where they arenecessary.
"It's also a lot of fun. I can guarantee that 100%."--Arthur C.Clarke
"Dewdney retells with charm and wit magnificent morsels ofmathematical mayhem discovered by his army of volunteer 'abusedetectives.' From 'sample trashing' to 'numerical terrorism,' from'percentage pumping' to 'dimensional dementia,' 200% of Nothingplumbs the depths of innumeracy in daily life and reveals whatordinary people can do about it.
A rich, readable, instructive, and persuasive book."--Lynn ArthurSteen, Professor of Mathematics, St. Olaf College
"It's also a lot of fun. I can guarantee that 100%."--Arthur C.Clarke
"Dewdney retells with charm and wit magnificent morsels ofmathematical mayhem discovered by his army of volunteer 'abusedetectives.' From 'sample trashing' to 'numerical terrorism,' from'percentage pumping' to 'dimensional dementia,' 200% of Nothingplumbs the depths of innumeracy in daily life and reveals whatordinary people can do about it.
A rich, readable, instructive, and persuasive book."--Lynn ArthurSteen, Professor of Mathematics, St. Olaf College
194 pages, Paperback
First published January 1, 1993
3 people are currently reading
114 people want to read
About the author
A.K. Dewdney
26 books30 followersAlexander Keewatin (A.K.) Dewdney is a professor of computer science at the University of Western Ontario, a mathematician, environmental scientist, and author of books on diverse subjects.
Wanderers of cyberspace may discover something about my life as a mathematician and computer scientist, environmental scientist, conservationist, and author of books and articles.
The name "Keewatin" is an Ojibway word meaning "north wind."
The name ":Dewdney" is from the French/Jewish name, "Dieudonne."
Wanderers of cyberspace may discover something about my life as a mathematician and computer scientist, environmental scientist, conservationist, and author of books and articles.
The name "Keewatin" is an Ojibway word meaning "north wind."
The name ":Dewdney" is from the French/Jewish name, "Dieudonne."
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Displaying 1 - 11 of 11 reviews
December 17, 2021
ENGLISH: I have written several posts in my blog dealing with this book's subject matter. This one, for instance: http://populscience.blogspot.com/2020....
Now that I've re-read Dewdney's book, I've prepared a new post speaking about this book. The examples of innumeracy are many, and during previous years I had collected a few.
ESPAÑOL: He escrito en mi blog varios artículos sobre el mismo tema que este libro. Por ejemplo, este: https://divulciencia.blogspot.com/202....
Ahora que he vuelto a leer el libro de Dewdney, he preparado un nuevo artículo en el que lo menciono. Hay muchos ejemplos de anumeralismo. En años anteriores he recopilado bastantes.
Now that I've re-read Dewdney's book, I've prepared a new post speaking about this book. The examples of innumeracy are many, and during previous years I had collected a few.
ESPAÑOL: He escrito en mi blog varios artículos sobre el mismo tema que este libro. Por ejemplo, este: https://divulciencia.blogspot.com/202....
Ahora que he vuelto a leer el libro de Dewdney, he preparado un nuevo artículo en el que lo menciono. Hay muchos ejemplos de anumeralismo. En años anteriores he recopilado bastantes.
December 4, 2025
Engaging read that I sometimes found hard to follow. Really made me realize how many pockets of innumeracy I harbor without knowing it and inspired me to become not just more literate but more numerate.
Pull quotes/notes
"One of the detectives entered a dealership sales office ready to write a check for $10,000 of his carefully saved money. The model he wanted was out in the lot, waiting. The salesman's eyebrows shot up when the customer offered to pay cash for the car. 'Why do you want to pay cash when you could finance the car through us?'
The detective replied that he wanted to save the cost of financing. Even if he were to finance the car, he said, he would do it through the bank anyway, since the bank only charged 7.5 percent instead of the dealership finance rate of 11 percent. As the detective tells the story, the salesman didn't even blink. 'But don't you realize that you could still save money by financing with us?'
The detective was not prepared for this. He thought that the dealership would be grateful to receive a cash payment. He was further dismayed to see the salesman swing over to a computer terminal and type in some numbers. The computer paused for a moment, then regurgitated the numbers in the form of intimidating financial data. The printout showed that a monthly payment of $327 would pay off the $10,000 car in 36 months with a total financing cost of $1,786. The statement further claimed that the customer's $10,000, left in a savings account at 7.5 percent, would earn $2,514 over the same period.
'Look at that! If you leave your hard-earned money in a term deposit, you can make the difference between $2,514 and $1,786. Let's see. That works out to $728.'
Thinking furiously, the detective hesitated while the salesman gave him a look reserved for small children and fools. 'But, uh, what about the $327 that I pay every month? Where's that going to come from?'
The salesman spread his hands and laughed heartily.
'Look, it's not my business where the money comes from. Frankly, you're the first person I've talked to who doesn't understand the system. But, hey, it's your decision!'
The abuse detective recovered his composure, certain that he had found the chink in the salesman's armor. They argued but the salesman did not relent. The detective passed up the purchase and went home with the printout in his hand. At home he got out his trusty calculator and went to work. Suppose he bought the car with the $10,000 outright, but built a fund with the monthly payments of $327 the salesman had wanted him to make on the car. He added in payment after payment, compounding at the bank's rate of interest as he went.
In about ten minutes he had the answer. After 36 months the fund would have swelled to $3,171.
Next day, he returned to the dealership to present his results to the car salesman. By buying the car outright and using the monthly payments, he would be $3,171 richer, much more than the mere $728 the salesman had claimed for financing through the payments and investing the $10,000. By neglecting to mention this, the salesman had tried, in effect, to bilk the detective out of the difference in the two amounts, namely
$2,443.
Now it was the salesman's turn not to understand the argument. He kept claiming that the fund was irrelevant to the debate! To this day, the detective isn't absolutely certain whether the salesman was innumerate or stubborn." (12-13) I had to read this example over at least ten times and I'm still not sure I fully get it. Prime example of innumeracy, I suppose
"Anthropologists like to imagine that the human brain evolved as the result of making and using tools. Whether or not such male-oriented theories resulted from the gender of most anthropologists, it is amusing to imagine that tool use had little or nothing to do with the development of human intelligence.
It makes more sense, when you think about all the complexities of human relationships and the tremendous benefits conferred by cooperation, to suppose that human evolution was driven entirely by the need to analyze relationships and predict the behavior of others. Toolmaking, considered as a mathematical activity, is utter child's play by comparison. Any fool can see where to knock the next chip off a flint spear point." (147)
"The incredible expanding Toyota of Chapter 1, for example, acquired 2 additional feet when the width of the car was increased by 9 inches. The surprise in this case is that mere inches should give rise to feet. Of course it's not surprising at all when you realize that the addition of 9 inches takes place across the entire area of one side of the passenger compartment. It might be fun to run the calculation of volume backward, in effect, to see just how big the Toyota passenger compartment was to begin with.
What area of the compartment would give you a 2-cubic-foot expansion when the compartment is expanded sideways by 9 inches?
The most powerful single idea in mathematics is the notion of a variable. You have already seen how the letter A could be made to stand for an amount of money or the number of animals in a herd. A letter or symbol can also stand for the area of the side of a passenger compartment. The great creative act of the mathematician follows: 'Let A be the area of the compartment side.' But when you multiply A by 9 inches to get an increase in volume of 8 cubic feet. you're in a position to know something about the Honda passenger compartment. After all, 0.75 × A = 8.
One of the simpler rules of algebra tells you that both sides of an equation can be multiplied or divided by the same number without violating the equality. If you divide both sides of the last equation by 0.75, you will get A all by itself on the left side of the equation and 10.666 on the right.
A = 10.666
In other words, you now know that the passenger compartment, if expanded sideways all over by 9 inches, must have had an area of 10 2/3 square feet. This isn't much. In order to have this area, a compartment that is only 3 feet high, for example, could not be much more than 3 feet, 6 inches long from front to back." (158-159) this was the other example that had my scratching my head
"How can it be that an automobile that's a mere nine inches larger on the outside gives you over two feet more room on the inside? Maybe it's the new math!
By appealing to 'the new math,' an experimental method for teaching mathematics introduced in the 1970s, the advertiser sent a signal to the innumerate public: 'Don't even try to think about this one. It's beyond you!'
The new math, an educational fad that is happily fading, promised to enhance the scientific and mathematical literacy of a new generation by introducing the language of set theory, logic, and other mildly arcane topics early in the curriculum.
Meanwhile, the old math, specifically the simple geometry of volumes, handles the Toyota miracle pretty well.
A 9-inch increase in any of the Toyota's three principle exterior measurements, (height, length, width) can not possibly produce a change of 2 linear feet in any one of the interior dimensions. This suggest that the 'two feet more room' refers not to length but to volume, two cubic feet to be precise. So should we be impressed when a mere 9-inch increase on the outside produces an additional two cubic feet inside? In fact, we should expect an even larger increase.
Look at the dimensions of the generic passenger compartment shown in Figure 1, which are 3 feet (height) by 6 feet (Length) by 4 feet (width). The volume is: 3 x 6 x 4 = 72 cubic feet. Any way you calculate the volume with an added 9 inches, the resulting increase is much larger than 2 cubic feet. Increasing its width by 9 inches, for example, increases its volume by a whopping 13.5 cubic feet: 3 x 6 x 4.75 = 85.5. Why, then, did Toyota claim such a small increase in the volume of its compartment? Did the company perhaps simply get its figures wrong?
Must be the new math!" (17) this part at least made sense once I realized the dimensions were in feet and not inches
Pull quotes/notes
"One of the detectives entered a dealership sales office ready to write a check for $10,000 of his carefully saved money. The model he wanted was out in the lot, waiting. The salesman's eyebrows shot up when the customer offered to pay cash for the car. 'Why do you want to pay cash when you could finance the car through us?'
The detective replied that he wanted to save the cost of financing. Even if he were to finance the car, he said, he would do it through the bank anyway, since the bank only charged 7.5 percent instead of the dealership finance rate of 11 percent. As the detective tells the story, the salesman didn't even blink. 'But don't you realize that you could still save money by financing with us?'
The detective was not prepared for this. He thought that the dealership would be grateful to receive a cash payment. He was further dismayed to see the salesman swing over to a computer terminal and type in some numbers. The computer paused for a moment, then regurgitated the numbers in the form of intimidating financial data. The printout showed that a monthly payment of $327 would pay off the $10,000 car in 36 months with a total financing cost of $1,786. The statement further claimed that the customer's $10,000, left in a savings account at 7.5 percent, would earn $2,514 over the same period.
'Look at that! If you leave your hard-earned money in a term deposit, you can make the difference between $2,514 and $1,786. Let's see. That works out to $728.'
Thinking furiously, the detective hesitated while the salesman gave him a look reserved for small children and fools. 'But, uh, what about the $327 that I pay every month? Where's that going to come from?'
The salesman spread his hands and laughed heartily.
'Look, it's not my business where the money comes from. Frankly, you're the first person I've talked to who doesn't understand the system. But, hey, it's your decision!'
The abuse detective recovered his composure, certain that he had found the chink in the salesman's armor. They argued but the salesman did not relent. The detective passed up the purchase and went home with the printout in his hand. At home he got out his trusty calculator and went to work. Suppose he bought the car with the $10,000 outright, but built a fund with the monthly payments of $327 the salesman had wanted him to make on the car. He added in payment after payment, compounding at the bank's rate of interest as he went.
In about ten minutes he had the answer. After 36 months the fund would have swelled to $3,171.
Next day, he returned to the dealership to present his results to the car salesman. By buying the car outright and using the monthly payments, he would be $3,171 richer, much more than the mere $728 the salesman had claimed for financing through the payments and investing the $10,000. By neglecting to mention this, the salesman had tried, in effect, to bilk the detective out of the difference in the two amounts, namely
$2,443.
Now it was the salesman's turn not to understand the argument. He kept claiming that the fund was irrelevant to the debate! To this day, the detective isn't absolutely certain whether the salesman was innumerate or stubborn." (12-13) I had to read this example over at least ten times and I'm still not sure I fully get it. Prime example of innumeracy, I suppose
"Anthropologists like to imagine that the human brain evolved as the result of making and using tools. Whether or not such male-oriented theories resulted from the gender of most anthropologists, it is amusing to imagine that tool use had little or nothing to do with the development of human intelligence.
It makes more sense, when you think about all the complexities of human relationships and the tremendous benefits conferred by cooperation, to suppose that human evolution was driven entirely by the need to analyze relationships and predict the behavior of others. Toolmaking, considered as a mathematical activity, is utter child's play by comparison. Any fool can see where to knock the next chip off a flint spear point." (147)
"The incredible expanding Toyota of Chapter 1, for example, acquired 2 additional feet when the width of the car was increased by 9 inches. The surprise in this case is that mere inches should give rise to feet. Of course it's not surprising at all when you realize that the addition of 9 inches takes place across the entire area of one side of the passenger compartment. It might be fun to run the calculation of volume backward, in effect, to see just how big the Toyota passenger compartment was to begin with.
What area of the compartment would give you a 2-cubic-foot expansion when the compartment is expanded sideways by 9 inches?
The most powerful single idea in mathematics is the notion of a variable. You have already seen how the letter A could be made to stand for an amount of money or the number of animals in a herd. A letter or symbol can also stand for the area of the side of a passenger compartment. The great creative act of the mathematician follows: 'Let A be the area of the compartment side.' But when you multiply A by 9 inches to get an increase in volume of 8 cubic feet. you're in a position to know something about the Honda passenger compartment. After all, 0.75 × A = 8.
One of the simpler rules of algebra tells you that both sides of an equation can be multiplied or divided by the same number without violating the equality. If you divide both sides of the last equation by 0.75, you will get A all by itself on the left side of the equation and 10.666 on the right.
A = 10.666
In other words, you now know that the passenger compartment, if expanded sideways all over by 9 inches, must have had an area of 10 2/3 square feet. This isn't much. In order to have this area, a compartment that is only 3 feet high, for example, could not be much more than 3 feet, 6 inches long from front to back." (158-159) this was the other example that had my scratching my head
"How can it be that an automobile that's a mere nine inches larger on the outside gives you over two feet more room on the inside? Maybe it's the new math!
By appealing to 'the new math,' an experimental method for teaching mathematics introduced in the 1970s, the advertiser sent a signal to the innumerate public: 'Don't even try to think about this one. It's beyond you!'
The new math, an educational fad that is happily fading, promised to enhance the scientific and mathematical literacy of a new generation by introducing the language of set theory, logic, and other mildly arcane topics early in the curriculum.
Meanwhile, the old math, specifically the simple geometry of volumes, handles the Toyota miracle pretty well.
A 9-inch increase in any of the Toyota's three principle exterior measurements, (height, length, width) can not possibly produce a change of 2 linear feet in any one of the interior dimensions. This suggest that the 'two feet more room' refers not to length but to volume, two cubic feet to be precise. So should we be impressed when a mere 9-inch increase on the outside produces an additional two cubic feet inside? In fact, we should expect an even larger increase.
Look at the dimensions of the generic passenger compartment shown in Figure 1, which are 3 feet (height) by 6 feet (Length) by 4 feet (width). The volume is: 3 x 6 x 4 = 72 cubic feet. Any way you calculate the volume with an added 9 inches, the resulting increase is much larger than 2 cubic feet. Increasing its width by 9 inches, for example, increases its volume by a whopping 13.5 cubic feet: 3 x 6 x 4.75 = 85.5. Why, then, did Toyota claim such a small increase in the volume of its compartment? Did the company perhaps simply get its figures wrong?
Must be the new math!" (17) this part at least made sense once I realized the dimensions were in feet and not inches
October 6, 2008
09/15/06
I normally enjoy books like 200% of Nothing. The book claims to show the importance of being numerate but the examples used are simplistic, obvious and humorless. At least the book is a short and quick read, coming in shy of 200 pages.
There isn't much in terms of new examples with in 200% of Nothing. Anyone with even the minimum of interest will have heard of these examples and their solutions. A perfect example is the "Monty Hall" puzzle. Another chapter languishes over tossing coins. Coin toss odds are about the most basic of examples, twenty pages really don't need to be spent on the subject!
The book might be more interesting for less numerate readers. My husband and I have both read 200% of Nothing and agree that the examples are basic and the author's attitude towards his audience is rather condescending. A better book on the subject is How to Lie with Statistics by Darrell Huff.
I normally enjoy books like 200% of Nothing. The book claims to show the importance of being numerate but the examples used are simplistic, obvious and humorless. At least the book is a short and quick read, coming in shy of 200 pages.
There isn't much in terms of new examples with in 200% of Nothing. Anyone with even the minimum of interest will have heard of these examples and their solutions. A perfect example is the "Monty Hall" puzzle. Another chapter languishes over tossing coins. Coin toss odds are about the most basic of examples, twenty pages really don't need to be spent on the subject!
The book might be more interesting for less numerate readers. My husband and I have both read 200% of Nothing and agree that the examples are basic and the author's attitude towards his audience is rather condescending. A better book on the subject is How to Lie with Statistics by Darrell Huff.
November 9, 2018
Not a book for those with a basic understanding of the mathematical concepts of probability and statistics. I only found the last two chapters to be useful, while the first 10 kind of baby stepped through ideas leaving the explanations to the end of the book.
August 11, 2025
A bit tedious.
April 22, 2013
Innumeracy is a more widespread plague than is illiteracy, yet we don't seem to pay it any attention or mind. This is a mistake, as Dewdney handily points out. Reading this book, I was proud that the examples cited therein are things I no longer fall for, having read enough books on the subject to protect me heartily against such misinformation. Prouder still was that I had read several books in the bibliography. Where this work stands out a bit from the others is that the author shows how easy it is NOT to be innumerate, and patiently shows the reader how. Works like these are of paramount importance, but an entire movement will need to be created to move innumeracy front and center.
July 10, 2013
The book started of very interesting but quickly became quite repetitive.
It is interesting to see how many math abuses there are in advertising and the media. Part due to innumeracy and part due to and intentional desire to mislead the public.
It is interesting to see how many math abuses there are in advertising and the media. Part due to innumeracy and part due to and intentional desire to mislead the public.
January 24, 2016
200% of Nothing focuses primarily on how mathematical and statistical abuse can be used to mislead the public. Dewdney's text is quite in-depth and can sometimes be a bit confusing as he references to so many statistics. However, it may be worth a read if you are intersted in mathematics.
January 14, 2008
I recently re-read this book...it has all types of misrepresentation of facts...it will make you laugh, it will make you cry.
January 4, 2009
Some things I already knew, but mostly new to me. Enjoyed reading this book.
October 14, 2017
This is a well written accessible text which shows that we are all capable of mathematical thinking, and mathematical misconceptions. broken into nice short sections with well explained examples, this book opens math up for everyone to enjoy.
Displaying 1 - 11 of 11 reviews