If you have never tried using Thangles before to make your half square triangles you might like them. There is no math. The only thing I do different from the directions is cut the fabric a little wider than 1/2". I like to have a little bit of wiggle room. It only adds an extra trim step.
I'm off to California for a week to see my dad. I will take my yo yo's so I don't go through complete withdrawal from sewing.