You are right, I became frustrated as I found that you did not care to help me when I expressed my doubt in post 07-26-2016 8:44 PM.

I am sure it is completely obvious to yourself what you mean, but not to me. This may partly be due to the fact that English is not my mother tongue. But it may also be due to inexact description of the problem! You could have done as I did namely showing exact spreadsheet/calculator examples and thus prevent any need for guesswork.

I have no desire at all to ridicule anyone (and have never been accused of that after more thousands posts) but neither I want to make guesses as to what a questioner mean.

Your problem may be a rounding issue (I'm not sure) so I give a link to one of many, many articles on that subject:

https://support.microsoft.com/en-us/kb/42980

Be warned however that floating point mathematics is a huge subject.

You also might consider to ask your question again in a new thread and then hopefully someone else will step in to help you. That actually was my way of thinking when I wrote: I will stop here.

Finally - your PI comment may be a joke, who knows, but it actually confused me which again may be due to my lack of knowledge of the finer nuances of the English language. And by the way - I have never and will never claim myself as an expert. You may be referring to the fact that on this site I am called 'Competent Performer', but I have had absolutely no influence on that. I am just an ordinary Excel user who now and then tries to help other Excel users.