How many stars are there?

Answer 1

There are an estimated 100 to 200 billion galaxies.

Scientists estimate that our Galaxy (The Milky Way) contains 200 to 400 billion stars.

So taking a conservative number of 100 billion stars per galaxy, gives an approximate total of 10,000,000,000,000,000,000,000 stars. (which is 10 sextillion)
It is unknown. The Milky Way galaxy contains an estimated 200 billion stars and there are an estimated 100 billion galaxies in the observable universe. However, our galaxy is significantly larger than most. That said, if we assume the average galaxy has 10 billion stars then we arrive at an estimate of 1,000 billion billion stars, or about 1 sextillion stars.

Answer 2

There are estimated to be around 100 billion stars in our Milky Way galaxy, and there are an estimated 100-200 billion galaxies in the observable universe. This means there could be around 10^24 stars in the observable universe.