What technique do astronomers primarily use to estimate the total number of galaxies?

Answer

Applying density counts from a tiny, focused patch of sky to the entire celestial sphere

The technique involves intensely studying a minuscule, seemingly empty patch of sky, counting the galaxies present, and then extrapolating that density across the entire celestial sphere.

What technique do astronomers primarily use to estimate the total number of galaxies?
galaxiesastronomyuniversecosmosestimation