Flippin’ Wizardry

Because I’m a math teacher, my services as demystifier of mathematical phenomena are sometimes requested by family and friends who find themselves sufficiently mystified by something mathematical.  Recently I’ve had a few people send me the link to the YouTube video, “How do japanese multiply??” [sic]

Based on some of the comments (e.g., “What the [flip] is this wizardry?”), there are at least a few people in the world who might like an explanation.  Here’s the original video, followed by my narrated solution, plus, for the nerdily inclined, a bonus example in base 6!  Can you imagine anything more fun?

Actually, if you want a much more interesting multiplication algorithm, take a look at Russian Peasant Multiplication.  Now that’s some [binary] wizardry.

…and the response…