I'm glad you asked, and your math is not fishy (carp-like). [I've been claiming 131 billion was the best answer, and I think it might be the 125 billion. I suppose someone could actually count the no. of stars in the image assumed to have 10,000 galaxies. Maybe they have by now.]
Originally Posted by Arneb
Here's a thread from 2009 when the HUDF info came upon us....
I think the HUDF (Hubble Ultra Deep Field) is the famous million second exposure taken over the course of several months.
As I recall, the HDF came first and with great success. This was followed by a southern version to see if it made sense to make extrapolations. The south gave similar galaxy counts.
I didn't check my old link to the camera sensor specs., but it looks like 125 billion may be a reasonable estimate of galaxies, though this will increase since this is not the earliest period for galaxy formation for the visible universe, exluding all regions beyond.
We know time flies, we just can't see its wings.