 A New Proof of The Four Colour Theorem  Ashay Dharwadker
An article presenting a proof of the four color theorem that uses group theory and Steiner systems, illustrated using a map of Madhya Pradesh and adjoining states in India. Introduction; Map Colouring; Steiner Systems; Eilenberg Modules; Hall Matchings;
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 NewsHour Extra: Math and Economics  MacNeilLehrer Productions; PBS
Lesson plans, stories written for students, and reports from the NewsHour with Jim Lehrer, the nightly news broadcast on PBS. See also the articles written for students based on NewsHour stories.
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 New Teachers and the Job Market  Key Issues in Mathematics at the Math Forum
Links to sites with a variety of organization, resources, and information for those seeking jobs as mathematicians or that require a knowledge of mathematics.
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 Newton's Castle  Steve Feld
Learn about color, optical illusions, how cars appear to roll uphill on "magnetic mountains," why dogs chase cars, and more; then test your learning with the online quiz. Also, see quotations and a timeline of Newton's life. With a bibliography and webliography.
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 Newton, Sir Isaac (Funk & Wagnalls Multimedia Encyclopedia)  Lycos Zone: Mathematics
A short biography of Sir Isaac Newton (16431727), focusing on The Fluxional Method, Optics, and The Principia.
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 New York City HOLD National  Elizabeth Carson
This advocacy organization's mission begins: "The performance of American students in mathematics is mediocre at best. Reform efforts over the past two decades have only made matters worse. We are advocates for school mathematics education reforms that
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 Next in Line  Ivars Peterson (MathLand)
Number sequences present all sorts of intriguing puzzles and patterns. Consider the sequence of counting numbers: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 .... Now, take out every second number, leaving: 1 3 5 7 9 11 13 15 ...; form the cumulative totals
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 Nice Guys Finish First (Sometimes) (MatheMUSEments!)  Ivars Peterson (Math Muse for Kids)
There's trouble in the schoolyard. A kid has accused you and your pals of doing something you shouldn't have. You have to decide whether to stick with the gang or go your own way. You're not completely sure you can trust your friends, so you face a tough
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 Nine Primes in a Row  Ivars Peterson (MathTrek)
...number aficionados Harvey Dubner of New Jersey, Paul Zimmermann of INRIA Lorraine in France, Tony Forbes of Great Britain, and Nik Lygeros and Michel
Mizony of Claude Bernard University in Lyon, France, mounted a campaign and solicited computational
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 A Nobel Formula  Keith Devlin (Devlin's Angle)
The discovery of a single mathematical formula in 1970 led to this year's Nobel Prize for economics, shared between Stanford University professor of finance (emeritus) Myron Scholes and economist Robert C. Merton of Harvard University. The prize would
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 The Nobel Prize in Physics – Educational  The Nobel Foundation
Step through explanations of physics concepts, some with Flash activities: explore hidden worlds with microscopes (as developed by laureates Zernike, Ruska, Binnig and Rohrer), look into the interior of matter (from Chadwick to van der Meer), and take
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 The NODE Learning Technologies Network  The NODE Learning Technologies Network
theNode.org provides networked support for instructors, trainers, designers and administrators with a professional interest in teaching with technology. Register for membership online. Internet resources for the study and teaching of mathematics include
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 Noga Alon
Noga Alon researches combinatorics, graph theory, their applications to theoretical computer science, combinatorial geometry and number theory, and the relationship of combinatorial algorithms and circuit complexity. Some of his papers, along with a
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 Noise Removal from Images  J. A. Sethian
A paper and movie on noise removal. Level Set Methods exploit the fact that curves moving under their curvature smooth out and disappear. The idea is to view the pixel values as a topographic map; the intensity (somewhere between white and black) at each
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 NonEuclidean Geometry  MacTutor Math History Archives
Covers Euclid's Elements through the end of the 1800's, with 23 references (books/articles).
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 NonEuclid  Joel Castellanos, Joe Dan Austin, Ervan Darnell
A Java program offering straightedge and compass constructions in hyperbolic geometry for high school and college students. A compressed version for PCs may be downloaded for use offline. The site includes an introduction to hyperbolic geometry, plus
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 Nonius  Jaime Carvalho e Silva
Nonius  Projecto Computação no Ensino da Matemática  Arquivo Electrónico de Matemática. History of mathematics; mathematics topics, mathematics teaching, technology in teaching, and links to relevant mathematical
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 Nonlinear Physics Group  Technical University, Darmstadt, Germany
A research group whose research areas include sonoluminescence, levitated drops, and acoustic and optically induced cavitation (view MPEG movies of bubbles!) A Java applet, Nonlinear Dynamics Online, provides visualizations of data sets: you may use
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 Nonlinear Systems Laboratory  Massachusetts Institute of Technology
A group dedicated to the analysis of nonlinear systems: list of publications (some abstracts are available online) and animations of a robot arm catching a ball and a paper airplane.
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 Nonsexist Solution of the Menage Problem  Bogart, Doyle
A paper that appeared in the American Mathematical Monthly. The ménage problem asks for the number of ways of seating couples at a circular table, with men and women alternating, so that no one sits next to his or her partner. The paper presents
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 The Normal Curve and Galton's Board  Paul Trow
Describes a mechanical device, invented by the nineteenthcentury mathematician Francis Galton, that illustrates the Central Limit Theorem, by showing how a binomial distribution approximates a normal distribution.
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 Northern Ireland Statistics and Research Agency (NISRA)
The department of the United Kingdom government that collects statistics about Northern Ireland. Includes tables and graphs of key socioeconomic statistics, which are available for download as Lotus 123 worksheets; demographic data, available in Lotus
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 Northwest to the Pole and TwoHeaded Coins (Math Chat)  Frank Morgan; Christian Science Monitor
Suppose you start at the earth's equator and travel continuously northwest until you reach the North Pole. What does your path look like? How long is your path?
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 NOVA Online: Hunting the Hidden Dimension  Public Broadcasting System (PBS)
The PBS television series NOVA has produced a program about fractals, their impact on the world of mathematics, and the way they're shaping our understanding of nature. In addition to the program itself (in five chapters), the website offers a program
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 NOVA Online: The Proof  WGBH, Public Broadcasting System (PBS)
For over 350 years, some of the greatest minds of science struggled to prove what was known as Fermat's Last Theorem  the idea that a certain simple equation had no solutions. This site includes an interview with Andrew Wiles (the man who spent seven
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 NRICH Maths, the Online Maths Club  Univ. of Cambridge, UK
A project that aims to establish a permanent national centre for curriculum enrichment to provide mathematical learning support for very able children of all ages. The learning and enjoyment of mathematics are promoted through an Internet Newsletter and
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 Null Science  Bruce Bower  Science News Online
A growing number of psychologists charge that their field needs to wean itself from the mindless application of certain statistical practices, especially a technique known as null hypothesis or significance testing, where the investigator typically gathers
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 numb3rs blog  Mark Bridger, Department of Mathematics, Northeastern University
A blog where math professor Bridger posts mathematical comments on the TV show "Numb3rs". Dating back to February, 2005, posts include "Math and March Madness" and "Random motion and FokkerPlanck" and "Acoustic fingerprints and the JFK assassination"
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 The Number of Latin Rectangles [PDF]  Peter Doyle
A paper that shows how to generate an expression for the number of kline Latin rectangles for any k. The computational complexity of the resulting expression, as measured by the number of additions and multiplications required to evaluate it, is on the
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 Numbers in the World (Math Chat)  Frank Morgan, MAA Online
Select the best occurrence in the world of each number from 1 to 10. For example, 12 is the number of eggs in a dozen or the number of months in a year... with winning reponses. Also: Math Chat has received a number of mathematical jokes, most of them
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 Number theory  Dario Alpern
A collection of calculators, tables, and articles about number theory, with an applet that is able to factor large numbers and a quadratic diophantine equation solver.
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 Number Theory: Historical things  Keith Matthews, Dept. of Math, University of Queensland, Brisbane, Australia
Biographies of past number theorists and various items of historical interest, including prizes, photos, and mathematical family trees.
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 Number: What Is "How Many"?  B. Sidney Smith; Math Academy Online/Platonic Realms
A "minitext" introducing fundamental concepts in elementary number theory and the foundations of mathematics. Includes discussions of basic set theory; natural numbers; integers; rational, irrational, and real numbers. Also gives a brief list of suggested
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 Numeracy and Quantitative Literacy  EXTEND  Perspectives in Mathematics Education
Links to articles on diverse views on the quantitative demands of today's society and the relation of quantitative literacy to mathematics education.
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 Numeracy in the News  The Mercury/University of Tasmania
Newspaper articles collected from the Tasmanian (Australia) metropolitan daily newspaper, The Mercury, to represent the five areas of the Chance and Data curriculum (Data Collection and Sampling, Data Representation, Chance and Basic Probability, Data
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 Numerical Analysis Digest Search Interface  Netlib
The NA Digest is a collection of articles on topics related to numerical analysis and those who practice it. All issues are indexed using Glimpse. To execute a search, enter a phrase or word into the form and choose the appropriate settings for your query.
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 NYC HOLD  Bas Braams and Elizabeth Carson, editors
Honest Open Logical Debate (HOLD) on Mathematics Education Reform addresses mathematics education in the New York City schools. Organized into Issues in Mathematics Education, Curriculum Reviews, Standards, New York City Issues, Call to Action, NYC News
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 Occam Press  Peter Schorer
"The skeptical mathematician is invited to improve upon the current implementations of the 3x + 1 strategy...." In addition to the Collatz conjecture, Schorer offers a simple proof of Fermat's Last Theorem, articles on Occam's Razor and programming,
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 Occupational Outlook Quarterly Online  U.S. Bureau of Labor Statistics (BLS)
A journal about jobs and careers covering new, emerging, and unusual occupations, training opportunities, salary trends, results of new studies, etc. Includes summaries and excerpts from articles, with full text available for download in PDF format and
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 Oceania  Mathematics and the Liberal Arts  Todd Hammond
Notes on published articles: a resource for student research projects and for teachers interested in using the history of mathematics in their courses. Many pages focus on ethnomathematics and on the connections between mathematics and other disciplines.
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 Office for National Statistics  Government Statistical Service, United Kingdom
The United Kingdom agency that coordinates national statistics. Tables of key social, economic, and environmental data, press releases, catalogue of publications, articles, and a newsletter. Information about the British census, including articles in
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 Of Men, Mathematics, and Myths  Keith Devlin (Devlin's Angle)
"With the Unabomber now firmly implanted in the public psyche as "a mathematician," the caricature of the mathematician as the misunderstood, antisocial loner has received a considerable boost. That much of mathematics these days is done by two or more
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 Of What Does Mathematical Knowledge Consist?  Annie and John Selden; Mathematical Association of America
Answers to epistemological questions such as "Does mathematical knowledge consist of competencies, or in seeing connections between mathematical concepts and results, or between various representations of a single concept?" Sections include Kinds of Mathematical
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 Old and New Arithmetic  Ivars Peterson (MathLand)
"Three merchants have invested their money in a partnership..." This problem appears in a mathematics textbook known as the Treviso Arithmetic. The original book, written in a Venetian dialect, had no formal title, and its author is unknown. Treviso is
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 Oliver Knill
Research, teaching, and media by this preceptor in Harvard's math department. Knill began in dynamical systems, tackling first ergodic and spectral theoretical questions, then probability theory and elementary number theory. This led to his "passion for
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 Once in a Millennium (Math Chat)  Frank Morgan, MAA Online
Challenge: The year 2000 can be represented as the sum of consecutive integers:
2000 = 398 + 399 + 400 + 401 + 402. The year 2001 can be represented as the sum of consecutive integers: 2001 = 1000 + 1001. In fact, every year in the millennium from 2000
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 On Constructivism  Susan Hanley
"The constructivist approach opens new avenues for learning as well as challenges for the teacher trying to implement it." Hanley outlines problems in traditional teaching methods, describes constructivism as a possible solution, and reviews research
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 On Deciding Whether a Surface is Parabolic or Hyperbolic [PDF]  Peter G. Doyle
An application of Rayleigh's method to the classical type problem for Riemann surfaces, which is really just the same random walk problem, only instead of walking around on an infinite graph the walker is diffusing around on a surface. The aim will be
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 OnePage Proof of Fermat: Critique (Math Chat)  Frank Morgan, MAA Online
Critique the following short proof of Fermat's Last Theorem sent in by
reader Rob Connelly. (In perhaps the biggest mathematics news of the century, Andrew Wiles recently came up with a very long and complicated proof of this 350year old problem.) Answer:
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 One size fits all?  Mike Robison; Mathematics Dept., Michigan State University
Age based tracking versus ability grouping in elementary school mathematics. A research paper on ability and age grouping that reviews the literature and makes suggestions for math education.
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