FEAR OF ALL SUMS: 3 MATH THEORIES BROUGHT TO YOU IN PLAIN ENGLISH If you've ever woken up in the middle of the night, broken out in a cold sweat: chances are you were dreaming of math. Chaos theory, relativity, golden proportions? It's the stuff nightmares are made of. But don't let it scare you; let it free you. mental_floss harnesses a "no hear" attitude to extreme mathematics, and we want you to tag along.

PHOTO FACTUAL: HOW INSTANT FILM WORKS HowStuffWorks.com There's no camera quite as magical as a Polaroid. Focus the lens, press a button, and immediately a full-size photograph begins to wriggle its way out. If you think it's magic though, you're severely mistaken. So, step out of the dark ages, and into the dark room as the folks at How Stuff Works shed a little light on instant film.

OH BOY, OBENTO: THE JAPANESE LUNCH BOX By Michael Stusser Talk about kicking it up a notch! While our moms (God bless 'em) might have spent a good 10 minutes or so whipping up a PB&J sack lunch, it's "normal" for Japanese mothers to spend up to an hour making their kid's obentos! Read on as Michael Stusser whizzes through the bizarre world of Japanese lunch art.

EVERYTHING YOU ALWAYS WANTED TO KNOW ABOUT SHINTO (BUT WERE AFRAID TO ASK) By Greg Salyer What makes a religion: an all-powerful god, a founder, scriptures, ethical codes... churches even? Well, not in Japan. And yet 86% of Japanese still consider themselves Shinto. If you've got questions (and you should have a lot right now), Prof. Salyer's got the answers.

FOR THE SAKE OF SAKE By Michael Stusser 2,000 years of beautiful tradition, from Imperial Court brew masters to ice-cold rice wines, and you're wondering why we're still living in the past? Put away your beer helmet and hide that funnel because mental_floss is going to learn you some culture, straight-up sake style!

LOPPING OFF MISCONCEPTIONS ABOUT THE GUILLOTINE From An Underground Education The National Abbreviator? The Patriotic Razor? You know something's wrong when your country has more than one pet name for its execution device. Those wacky French loved their guillotine, and Richard Zacks is here to tell all.

PLUS ALL THE USUAL DEPARTMENTS: [scatter_brained] PRESIDENTS, THE BOOK: LOLITA, SOMEWHERE BETWEEN 20 AND 30 FACTS ON JAPAN, KNOW YOUR DOUGH: THE EURO, 10 CURIOUS ORIGINS OF DELICIOUS PHRASES, THE QUIZ, MAKING SENSE OF CURRENT EVENTS: THE INTERNATIONAL, MONETARY FUND AND WORLD BANK, and plenty of USELESS KNOWLEDGE.