Math Forum Internet News

Volume 3, Number 49

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 7 December 1998                                   Vol. 3, No. 49


Glossary of Mathematical Mistakes | Classic Fallacies | The Why Files


Paul Cox's list of common mathematical mistakes committed 
by advertisers, the media, reporters, politicians, activists, 
and others. Cox analyzes everything from circular reasoning, 
graph errors, and spurious use of the law of averages to 
"factorectomy," gestalt geometry, and the "Kevin Bacon" game 
(six degrees of separation). Examples include:

 - Aftermath Counting (Dewdney) - what the press has a 
   tendency to do after a major disaster - the counting of 
   known casualties from the police, paramedics, hospitals, 
   and morgues, without considering duplication...

 - Gambler's Ruin - if a gambler stays in a casino long 
   enough he will eventually lose all of his money. This is 
   why casinos can pay out millions in winnings and still 
   stay in business...

 - The Object D'art Graph - A graph that lacks a standardized 
   y-axis in order to hide what the graph is really saying. 
   It can be a pretty graph suitable for framing but in fact 
   is absolutely useless...

 - Logical Fallacies - if you want to deceive the majority of 
   the people, use some of these in your arguments. (Note that 
   these are used consistently by politicians, lawyers, and 

 - "Looks Like" Geometry - the tendency to find significance
   in insignificant geometric patterns. The best example is 
   the "Face on Mars"...

Cox also accepts and discusses examples submitted by readers, 
which include the Monty Hall problem and Zohnerism (named for 
the student who petitioned to ban dihydrogen monoxide). See
his Mistake of the Month with its archive, the Raw Data
(the math behind the mistakes); Problems and Puzzles  
(in arithmetic, geometry, and algebra); and sources and links.



              CLASSIC FALLACIES - Philip Spencer

Mathematical "proofs" demonstrating that 1 = 2, that all 
people in Canada are the same age, that a ladder will fall
infinitely fast when pulled, and that every natural number
can be unambiguously described in fourteen words or less.

Each proof consists of several steps that allow readers to
look for the flaw, and then explain why it is or is not in
that step. 

A printed version of this material, suitable for use as a 
classroom module, is available from the site.


           THE WHY FILES - University of Wisconsin


An electronic exploration of the issues of science, math, 
and technology that lurk behind the headlines of the day. 
Included are a bimonthly feature on the science of everyday 
life, archived files, discussion forums, sports science and
puzzles, and science images. 

Search the site for math to find such pages as:

 - Coping with Multiples (massive multiple math quiz)

 - Counting Bacteria

 - Fantastic Fractals

 - Random Is as Random Does

 - Serious Statistical Secrets


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