How to Do Lattice Math

The kids and I have been viewing Basic Math from The Teaching Company. One thing we learned was how to do lattice multiplication. The video below is a very basic demonstration of the method. I don't think it's any faster than the traditional method of multiplication but the kids have a lot of fun doing it and showing off to visitors. If a new method gets them excited about doing math then I'm all for it!

I'll try to find a YouTube of a more complicated problem than the one shown in this video so you know what to do with larger numbers that need to carry. Hopefully, I'll have it posted in the next day or two. In the meantime, maybe you can figure it out for yourself.