Sew1096, I think you're right. There are six rows each side of the central row, to make it symmetrical, although it ways it's a 12 block. Well, it wouldn't be the first time.

this is a simple graph...put it on graph paper and declare each square to be 3 inches and then follow for cutting....this is the way i size all my quilt blocks (either up or down)...if you can put them on graph paper, you simply decide how large or small you want the block to be and then re-do your cutting instructions to fit.

I just came across this worksheet at Quiltmaker magazine. It may be helpful sometime.
It can be saved as a pdf.

http://www.quiltmaker.com/articles/R...ocks_Worksheet