making half quares
 

I use the zipper foot to sew the seam lines, this works great on smaller ones with out having to mark each block. On larger blocks I mark the middle of each block only as a guide... try it on scrapes first to see how it works for you. Marking each block
is so boring .. guess I worked improving production lines out puts to long always trying to save time ...

Happen to find this idea on Pinterest.com yesterday. The catch for this is that all eight half square triangles are going to be out of the same fabric, but it looks easy and very satisfying for quickness. Just thought I would pass it along.

http://pinterest.com/pin/240520436319198552/

By the way, I like your idea also :p

pinterest is using Eleanor Burns method. I love it. No math involved though, you just add 2 in for each size.
6 in blocks for 2 1/2 in sqs. 8 in for 3 1/2 in sqs etc.
Her triangle square up ruler makes it even easier since you only need to make ONE cut. You square up before you open the square and you can cut off the little tabs at the same time. It is a must have time saver.

That would make sense. I had not looked into where it came from, but love the idea anyway. Thanks for the update.