Tag Archives: arithmetic

The wizard’s rational puzzle (solutions, part 2)

Posted on November 9, 2018 by Brent

At long last, here is the solution I had in mind for the Wizard’s rational puzzle. Recall that the goal is to figure out the numerator and denominator of a secret rational number, if all we are allowed to do … Continue reading →

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The wizard’s rational puzzle (solutions, part 1)

Posted on October 24, 2018 by Brent

About two and a half months ago I posted a challenge involving a sadistic math wizard, metal cubes containing rational numbers, and a room full of strange machines. I’ve been remiss in following up with some solutions. (Go read the … Continue reading →

Posted in arithmetic, challenges, logic, programming, puzzles, solutions | Tagged , , , , , , , , | 3 Comments

The wizard’s rational puzzle (mind your p’s and q’s!)

Posted on August 7, 2018 by Brent

You have been abducted by a sadistic math wizard (don’t you hate it when that happens?). He ushers you into a plain but cozy-looking room, with a hardwood floor, a few exotic-looking rugs, and wood paneling on the walls. He … Continue reading →

Posted in arithmetic, challenges, logic, programming, puzzles | Tagged , , , , , | 15 Comments

More fun with Dirichlet convolution

Posted on January 5, 2017 by Brent

I’m back after a bit of a hiatus for the holidays! Last time we saw how the principle of Möbius inversion arises from considering the function from the point of view of Dirichlet convolution. Put simply, the Möbius function is … Continue reading →

Posted in number theory | Tagged , , , , , , | 1 Comment

Right answers for the wrong reasons

Posted on June 30, 2010 by Brent

Here’s a recent xkcd which as a math educator I found particularly funny. Some questions for my readers: What numbers besides 3 and 9 would “work” here? Do you have any particularly funny or interesting stories of students getting something … Continue reading →

Posted in arithmetic, humor, links | Tagged , , | 8 Comments

minim

Posted on November 4, 2009 by Brent

A fun game I discovered recently, minim. In each level you start out with a network of numbered nodes, and the object is to successively combine the nodes according to certain mathematical rules in order to end up with only … Continue reading →

Posted in games, links | Tagged , | 1 Comment