Take the tour ×  (Note: I'm more a backend developer, so please
forgive my lack of UX terminologies. Don't hesitate to edit the
text or the tags)  We are working on an online scientific
software with specific constraints about numeric inputs:    •
Inputs are made in a sort of treegrid. There are a few columns,
and only 1 or 2 with numeric input   • On very close rows,
figures can be extremely heterogeneous. The user can enter "1
000" in one row, "2,2435e-13" on the next one, then "0.037",
then "6,62355e9" on the fourth row, and so on   • Even if the
software is a scientific software, sometime the user entering
some data doesn't have a scientific background   • Data are
sometime copy/pastes from an external computation, and can be
something like "2.234234567456e-6"   • The software is
international, and numerical values display are really
different. A French user may try to input "1 453,23", in
Switzerland something like "5 234.43". Some other countries use
other thousand separators   • Our computations don't