Algebra for Knitting

So, I finished all of the pieces of the Seville jacket, and just have to knit the cable border that goes all around the edges. 72 inches of cable border. Based on the amount of yarn remaining, there's no way. So I knit up a bit, and did some calculations. The first one is to figure out the grams per inch of the 2" long knit sample.



5 grams of sample plus needle minus 3 grams per needle = 2 grams per sample, or 1 gram per inch. So, I need 70 additional grams of yarn.

I have 31 grams. Not nearly enough. So, I ordered another skein from Green Mountain Spinnery, with the hope that no one will notice a dye lot difference, as the cable section will look slightly different anyway.

This leaves me with one WIP, so off to figure out what is next!