You might be surprised to learn the drawing method does a simple decomposition as well, if you just stare long enough. In this case (4x10+2)(2x10+1) = 4x2x10x10

You might be surprised to learn the drawing method does a simple decomposition as well, if you just stare long enough. In this case (4x10+2)(2x10+1) = 4x2x10x10 + 4x10x1 + 2x10x2 + 2x1. And the number of tens of the products are just substituted by position. No more or less than any other multiplication algorithm for humans, but nice in that the sticks are fun to draw.