I'm trying to figure out how to make an inner sawtooth border and can't figure out how to make it...all I have is a black and white diagram of what the finished quilt should look like, no measurements, nada. I'm thinking that I would measure the length divide it into a reasonable amount of "teeth", add 1/2 in. and then (here's the math challenged part) get my square ruler out and measure across so I could make HST out of squares. Is there an easier way?