Just a thought if you are repeatedly doing the same calculation with different numbers. Any calculation I do repeatedly I have an ongoing spreadsheet I put it in. This eliminates potential error while punching numbers, allows me to see all the values after they have been entered, change only one to redo the calc, and I don't have to memorize the equations. I have it on a cloud drive so I can use it anywhere I have a signal.
"Life is an open book test, it helps if you open the book and read"