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Monthly Archives: January 2009
Carnival of Math #48, and Monday Math Madness #25
The 48th Carnival of Mathematics is posted at Concrete Nonsense. My favorite posts include Foxmath’s post about a strange iterated sequence involving pi and this amazing picture of a fractal cabbage. Also near and dear to my heart is Mark … Continue reading
Posted in challenges, counting, famous numbers, fractals, links
Tagged carnival, counting, fractal cabbage, monads, pi
1 Comment
More on repetend lengths
In a previous post, I noted that the length of the repetend (repeating portion of the decimal expansion) of a fraction with prime denominator p is at most p1, and in fact divides p1. I also said: In fact, there’s … Continue reading
Posted in group theory, number theory, pattern, primes
Tagged decimal, expansion, fractions, length, repetend
6 Comments
New bookshelf entry: The Annotated Turing
For my birthday I got, among other things, a copy of The Annotated Turing: A Guided Tour Through Alan Turing’s Historic Paper on Computability and the Turing Machine, by Charles Petzold. I haven’t finished reading it yet, but so far, … Continue reading
More on decimal expansions
Today, I’d like to answer some of the questions I raised in the Decimal Expansion Zoo: Which decimal expansions terminate, and which are repeating—and how does it relate to the denominator? As we know, the decimal expansion of every rational … Continue reading
Carnival of Mathematics and other links
The 47th Carnival of Mathematics has been put together by jd2718; go give it a read! Some of my favorite posts include factoring by puzzles, teaching binary numbers, the 2009 game, cliques of dichotomies, but there is lots of other … Continue reading
Predicting pi: pretty graphs and convergents
Recall the challenge I posed in a previous post: given the sequence of integers , what can you learn about (assuming you didn’t know anything about it before)? The answer, as explained in another post, is that you can learn … Continue reading
Posted in convergence, famous numbers, pattern, sequences
Tagged approximation, convergents, graphs, pi
5 Comments