Rambi,
Actually, it is a shame that someone sees the need to make fun of a well-intentioned question.
I for one,
(a) am an engineer .. so the sums are trivial but, you will see, my observations above are nowhere near as useful as some of the others
(b) have been flying for 35 years in aircraft ranging from rag and string to transport including considerable ground school instruction work and I have never heard of this approach .. so, just maybe, not everyone has the benefit of the lessons which someone gave you at an earlier stage in your career.
I would much rather see these sorts of questions keep coming up .... I am quite happy to learn from the better knowledge and experience of others ....