The small squares are 10 x 10 = 100 dots.
The big squares are 100 x 100, so 10,000 dots.
One row is 100 x 10,000 = 1 million dots (scroll right to see the whole row).
To get 1 billion, we need 1,000 rows (see below).
To get the number of stars in the Milky Way galaxy, we need 300 pages like this one side-by-side.