# Convention of digit grouping after decimal point

I read that different cultures have different ways of grouping digits before the decimal point for readability e.g. 1234567890 can be grouped as 1 234 567 890 (English), 12 3456 7890 (Chinese) or 1 23 45 67 890 (Indian), but is there an established convention for grouping digits of a real number after the decimal point for readability e.g. should 3.14159265358979 be grouped as 3.141 592 653 589 79, 3.14159 26535 8979 or something else?

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Interesting. I've never thought to worry about this. Using the spacing appropriate to the left-of-decimal digits, having fixed a language, seems appropriate, except that now it's the last group that may be too short, instead of the first (in the English and Chinese conventions.) – Kevin Carlson Aug 15 '12 at 11:25
I can't say much of this due to my brilliant ignorance in the issue, but I think the main motivation for grouping to the right of the decimal point, just as it is to the left, is for clearity, and if this is really so then I guess there can't really be any universal convention about it. – DonAntonio Aug 15 '12 at 12:03
It could be that the decimal point is an anchor from which both integer and fractional parts "grow" out of, leftwards and rightwards, respectively. – Gnubie Aug 15 '12 at 19:11
It also ensures the groups are aligned when using decimal tabs, i.e. aligning a column of numbers at the decimal point, e.g. to add them up: desktoppub.about.com/od/typelayout/ss/tabs_5.htm – Gnubie Aug 15 '12 at 19:12

let oneMillion = 1_000_000