Tag Archives: decimal

More fun with infinite decadic numbers

Posted on October 28, 2011 by

This is the sixth in a series of posts on the decadic numbers (previous posts: A curiosity, An invitation to a funny number system, What does “close to” mean?, The decadic metric, Infinite decadic numbers). Last time I left you … Continue reading →

Posted in arithmetic, infinity, number theory | Tagged , , , , | 4 Comments

More on repetend lengths

Posted on January 27, 2009 by

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 p-1, and in fact divides p-1. I also said: In fact, there’s … Continue reading →

Posted in group theory, number theory, pattern, primes | Tagged , , , , | 6 Comments

More on decimal expansions

Posted on January 21, 2009 by

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 →

Posted in number theory, pattern | Tagged , | 15 Comments

Decimal expansion zoo

Posted on September 23, 2008 by

In a comment on a previous post about rational numbers and decimal expansions, Steve Gilberg noted: I’ve been fascinated at how any multiple of 1/7 that’s not an integer repeats the same digits in decimal expression, only starting at different … Continue reading →

Posted in number theory, pattern | Tagged , , | 14 Comments

Rational numbers and decimal expansions

Posted on September 7, 2008 by

As you may remember from school, rational numbers have a terminating or eventually repeating (periodic) decimal expansion, whereas irrational numbers don’t. So, for example, 0.123123123123…, with 123 repeating forever, is rational (in fact, it is equal to 41/333), whereas something … Continue reading →

Posted in infinity, iteration, number theory, pattern | Tagged , , | 9 Comments