As very much a non-mathematician, his method does not seem remotely intuitive to me. Whether that opinion is invalid because of my lack of skill or more valid b

As very much a non-mathematician, his method does not seem remotely intuitive to me. Whether that opinion is invalid because of my lack of skill or more valid because I'm his intended demographic I'll leave up to you. For this very specific use case, I would call it sub-optimal, for the simple reason it takes all of five minutes to teach a class the formula by singing it to the tune of Frère Jacques. I haven't used the formula in over a decade but can still sing it.