You can do diffy q's without electronics? !! Hey, my niece and husband own the largest dairy farm in WI, combines included. OK, can't do FEA in my head, but I LOVE finding a straight line after doing log log transformations.
Only sraight lines after I do any kind of logs are the skid marks in the toilet bowl.
You must appreciate short lines after log log analysis. Thems are tough to come by. Where's waldo?
I am more prairie bred than WI, but I live to go fishing up there!