I think that's the first time I've seen my calculator shared by someone else
Made my day Rob, thank you!
I really enjoy thinking through things, but math is not my strong suit and I don't care to do it every time. I think it's important to understand the principles so you can make sure your answers are in the ballpark, but one of the ways to keep people doing something is to make it easy. Same thing with checklists, they have to be easy or else people discard them.
Anytime someone has given me a calculation question, I have tried to take the time to build the calculator for it so I can answer it faster in the future.