Is there a reasonable way to use numbers smaller than about 10^-6

[Geoff Canyon]

I'm calculating gravity across long and short distances. That means I need
to deal with the gravity of Earth (~9.8 m/s/s) and Europa (~10^-11 m/s/s)
at the same time, and it can get worse than that (Sedna, for example)
Ordinary math seems to peter out at 0.000001.

This puts 8.100e-13: put format("%1.3e", (1e0)/(1234567890123e0))

So is something like that the best way to go?

gc