Just this afternoon, I heard a quilter say that she likes to use panels and focus fabrics to make 9-patch pizzazz quilts.
I was curious as I had heard about those quilts but didn't really know what they looked like.
I came home and asked Google to show me some images of that pattern
https://www.google.ca/search?q=nine+...w=1366&bih=643
No help with the math but the quilts look interesting.