It's time for the October snippets, all of which come with a mathematical bent.
• Today would have been the late Martin Gardner's 96th birthday. In honor of his memory, check out one of his interesting surprises over at The Mathematical Tourist's post Martin Gardner’s Möbius Surprise.
Here's another mathematical surprise, courtesy of the Gardner fans over at G4G4:
Write out the alphabet in capital letters, starting with J:
Erase all letters that have left-right symmetry (such as A) and count the letters in each of the five groups that remain.
I won't spoil the surprise. Just try it.
• A while back, James Grime posted a video about the math behind an episode of Futurama. Unfortunately, because it used video from the show, it was taken down for copyright violations. Later, however, it was put back up, and wound up being removed. As of today, it's back up again.
If you click that link and it's down again, there's always the safe edit version. There's also plenty of Futurama-related math over at, strangely enough, Futurama Math.
• James Grime also has a nice article on non-transitive dice over at plus magazine. Basically, it's a way of making dice inherently unfair. The same approach can also be applied to coin flips. Interestingly, James Devlin points out that even a standard coin flip may be unfair.
• Since we've already covered dice and coins, how about winding up with playing cards? Over at the World of Playing Cards, you can easily lose an hour or a day just going through the different topics, including how playing card design and usage evolved in different countries!
No matter how well you think you know playing cards, you still might be hard pressed to figure out what's wrong with these playing cards.
I'll come full circle by bringing the topics of playing cards and math together by having you check out Johnny Ball’s ‘Two Wrongs Do Make a Right’ Trick. Try it out as in the description, and then read on to learn why it works!