I gave a short talk about my favorite math jokes at G4G15. G4G stands for the Gathering for Gardner, my favorite conference. Here is a joke about Heisenberg from my talk. * * * Heisenberg gets pulled over on the highway. Cop: “Do you know how fast you were going, sir?” Heisenberg: “No, but I know exactly where I am.” After my talk,...

Another cute geometry puzzle was posted on Facebook. Puzzle. An equilateral triangle in a plane has three vertices with known x-coordinates: a, b, and c. What is the side of the triangle? I want to describe three different solutions that the readers of the Facebook channel posted. But before doing so, let’s look at the problem’s symmetries....

The homework I give to my students (who are in 6th through 9th grades) often starts with a math joke related to the topic. Once, I decided to let them be the comedians. One of the homework questions was to invent a math joke. Here are some of their creations. Two of my students decided to restrict themselves to the topic we studied that week: sorting...

Here is an interesting puzzle by Ivan Mitrofanov. Puzzle. In front of my dog, Fudge, lies an infinite number of meatballs with a fly sitting on each of them. At each move, Fudge makes two consecutive operations described below. Eats a meatball and all the flies sitting on it at that time. Transfers one fly from one meatball...

I collect math jokes and, of course, show them to my family. From time to time, my family contributes. The first joke is by my son, Alexey. * * * When you board a train traveling East from Chicago to Boston at 60 miles an hour, you realize you are a part of the problem. And this one is one of mine. * * * A dyslexic’s...

These two puzzles were given to me by Andrey Khesin. Puzzle. My friend and I are going to play the following game at a casino. Each round, each of us (my friend, the dealer, and I) secretly chooses a black or white stone and drops it in the same bag. Then, the contents of the bag are revealed. If all three stones are the same color, my friend...