Tag Archives: negative

Infinite decadic numbers

Posted on October 19, 2011 by Brent

To recap: we’ve now defined the decadic metric on integers by where is not divisible by 10, and also . According to this metric, two numbers are close when their difference is decadically small. So, for example, and are at … Continue reading →

Posted in arithmetic, convergence, infinity, number theory | Tagged , , | 7 Comments

Minus times minus is plus

Posted on September 29, 2009 by Brent

I’ve seen several recent posts wondering about an intuitive explanation for the fact that “a minus times a minus equal to a plus”. I understand why people would wonder about this—the way it’s often taught, it seems to be just … Continue reading →

Posted in arithmetic | Tagged , , | 14 Comments