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What's Special About This Number?

What's Special About This Number?
What's Special About This Number? If you know a distinctive fact about a number not listed here, please e-mail me. primes graphs digits sums of powers bases combinatorics powers/polygonal Fibonacci geometry repdigits algebra perfect/amicable pandigital matrices divisors games/puzzles 0 is the additive identity . 1 is the multiplicative identity . 2 is the only even prime . 3 is the number of spatial dimensions we live in. 4 is the smallest number of colors sufficient to color all planar maps. 5 is the number of Platonic solids . 6 is the smallest perfect number . 7 is the smallest number of sides of a regular polygon that is not constructible by straightedge and compass. 8 is the largest cube in the Fibonacci sequence . 9 is the maximum number of cubes that are needed to sum to any positive integer . 10 is the base of our number system. 11 is the largest known multiplicative persistence . 12 is the smallest abundant number . 13 is the number of Archimedian solids . 17 is the number of wallpaper groups .

The Thirty Greatest Mathematicians Click for a discussion of certain omissions. Please send me e-mail if you believe there's a major flaw in my rankings (or an error in any of the biographies). Obviously the relative ranks of, say Fibonacci and Ramanujan, will never satisfy everyone since the reasons for their "greatness" are different. I'm sure I've overlooked great mathematicians who obviously belong on this list. Please e-mail and tell me! Following are the top mathematicians in chronological (birth-year) order.

Nerd Paradise : Divisibility Rules for Arbitrary Divisors It's rather obvious when a number is divisible by 2 or 5, and some of you probably know how to tell if a number is divisible by 3, but it is possible to figure out the division 'rule' for any number. Here are the rules for 2 through 11... The last digit is divisible by 2. 25 Spectacular Movies You (Probably) Haven't Seen Midnight in Paris Woody Allen’s latest places starving writer Owen Wilson in Paris with his fiancée, Rachel McAdams. Searching for inspiration for his incomplete novel, Owen begins taking strolls around the city at night where he discovers an unexpected group of people. I wish I could be more specific, but it would ruin the surprise. Tanya Khovanova’s Math Blog » Blog Archive » Divisibility by 7 is a Walk on a Graph, by David Wilson My guest blogger is David Wilson, a fellow fan of sequences. It is a nice exercise to understand how this graph works. When you do, you will discover that you can use this graph to calculate the remainders of numbers modulo 7. Back to David Wilson: I have attached a picture of a graph. Write down a number n.

Weierstrass functions Weierstrass functions are famous for being continuous everywhere, but differentiable "nowhere". Here is an example of one: It is not hard to show that this series converges for all x. In fact, it is absolutely convergent.

Number Names Here are large number names and their scientific notation equivalents. 1,000,000 = one million = 10^6 1,000,000,000 = one billion = 10^9 1,000,000,000,000 = one trillion = 10^12 1,000,000,000,000,000 = one quadrillion = 10^15 1,000,000,000,000,000,000 = one quintillion = 10^18 How to Read Mathematics This article is part of my new book Rediscovering Mathematics, now in paperback! How to Read Mathematics by Shai Simonson and Fernando Gouvea How To Analyze Data Using the Average The average is a simple term with several meanings. The type of average to use depends on whether you’re adding, multiplying, grouping or dividing work among the items in your set. Quick quiz: You drove to work at 30 mph, and drove back at 60 mph. What was your average speed? Hint: It’s not 45 mph, and it doesn’t matter how far your commute is. Read on to understand the many uses of this statistical tool.

6174 (number) 6174 is known as Kaprekar's constant[1][2][3] after the Indian mathematician D. R. Kaprekar. This number is notable for the following property: Take any four-digit number, using at least two different digits. (Leading zeros are allowed.)Arrange the digits in ascending and then in descending order to get two four-digit numbers, adding leading zeros if necessary.Subtract the smaller number from the bigger number.Go back to step 2. Probabilities in the Game of Monopoly® Probabilities in the Game of Monopoly® Table of Contents I recently saw an article in Scientific American (the April 1996 issue with additional information in the August 1996 and April 1997 issues) that discussed the probabilities of landing on the various squares in the game of Monopoly®. They used a simplified model of the game without considering the effects of the Chance and Community Chest cards or of the various ways of being sent to jail. I was intrigued enough with this problem that I started working on trying to find the probabilities for landing on the different squares with all of the rules taken into account.

Fibonacci Number The Fibonacci numbers are the sequence of numbers defined by the linear recurrence equation with Folding Paper in Half Twelve Times Folding Paper in Half 12 Times: The story of an impossible challenge solved at the Historical Society office Alice laughed: "There's no use trying," she said; "one can't believe impossible things." "I daresay you haven't had much practice," said the Queen. Through the Looking Glass by L. Carroll The long standing challenge was that a single piece of paper, no matter the size, cannot be folded in half more than 7 or 8 times.

Two-dimensional Geometry and the Golden section On this page we meet some of the marvellous flat (that is, two dimensional) geometry facts related to the golden section number Phi. A following page turns our attention to the solid world of 3 dimensions. Contents of this Page