**Tags**

Cartesian product, Japanese multiplication method, multiplication, Pillow (PIL fork), Python, Python code

On my regular blog I just posted about a Japanese visual multiplication method. It’s a cute trick that ties into the notion of grid multiplication techniques. (In general, multiplication techniques are of some interest due to the Mandelbrot set, which requires multiplying large numbers lots of times.)

It turns out code to generate the patterns was a lot easier than I thought it would be. The hardest part was generating the diagonal summing lines.