Visual multiplication is delightful

It's been ages since I last checked in with math-doodling funnylady Vi Hart's YouTube feed — too long. The latest installment's a great technique for visual multiplication (and binomial expansion!) that I wish I'd known when I was in school, and a little rumination on good sentence structure in mathematics.

Re: Visual Multiplication and 48/2(9+3)

(via Copyfight)