Question

How many galaxies do astronomers estimate there are in the Universe?

Answer 1

100 billion galaxies (100,000,000,000)

Explanation:

Astronomer's best estimates of the number of Galaxies in the observable Universe are One Hundred Billion. The astronomers counted the galaxies in a designated region, and then they multiplied their number up to estimate the number of the whole universe.

(http://www.physics.org/facts/sand-galaxies.asp)