Thanks for the tutorial. I realize now, after you showed me how to work it, that its a calculation I used to use in preparing in pharmaceutical intravenous fluids. I was ignoring the total weight after adding the vital. I can't remember the actual mathematics I was taught 36 years ago and used back then but the concept was that you wanted a final solution of a particular volume and percentage strength after adding another solution containing a different concentration. since the mass of the vital was trivial I wasn't counting it into the total mass.
The amount, mass, of vital, however, came out the same as my % calculation with the 0.6% factor for King Arthur vital, but my total flower/vital was now the correct 520 grams, at this size batch, the change is trivial but if making 50lbs...the induced error could be disastrous as the hydration would be way off as the gluten takes extra water. Thanks for the education...especially the revelation I made by trying different vitals, they can differ quite dramatically. I'll be sure to get a dig in on the wifey about her unknown % vital, even if it is organic. She doesn't weigh things like I do and just tosses and knows how much to use to get the effect she wants, don't you get annoyed with people like that?