It all starts with the equation a + b = c, which looks straightforward enough. Assume that a, b and c are positive integers that have no divisors in common other than 1; for example, the triple {1, 2, 3} meets this condition, and so does {4, 5, 9}.
Now let’s take the product of […]

Investors are constantly checking the stock ticker, gamblers check the point spread, and everybody is forever checking their e-mail. For a writerly type like me, however, the unshakeable obsession is checking my Amazon sales rank. Amazon.com calculates a sales rank for every book listed on its Web site, and updates the ranking hourly. Here’s a […]

I am pleased and proud to note that the previous posting in this space (A mathematical fable previsited) is doing double duty as a column for MAA Online, the Web presence of the Mathematical Association of America.
Just so I can’t be accused of favoritism, I’ll also mention the American Mathematical Society, where Tony Phillips’s Math […]

A year ago, in my American Scientist column, I was deconstructing the oft-told tale of Carl Friedrich Gauss and his boyhood triumph over a despotic schoolmaster. As the story goes, Gauss applied a bit of mathematical ingenuity to quickly solve a problem that the teacher had thought would keep the class busy for quite some […]