Thank you AnomalousMonk. I think the point you are making is that when summing digits: if we consider integers of the form abc say then -abc will always sum to 2a less than abc. 2a is always even so abc and -abc must always both be odd or both even. Hence no need to worry about absolute values for this purpose. Please forgive me if I have not expressed this in a correct formal way - it is over 40 years since I did any mathematics. Your point is excellent.

In reply to Re^2: Newbie question by oldB51
in thread Newbie question by oldB51

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