the sun has the average mass of all the stars, then divide the mass of the galaxy by the mass of the sun.
Specifically, she wants you to do this division by subtracting exponents. 10^30 has 30 zeroes after it. 10^42 has 42 zeroes. That's a difference of 12 zeroes, which is a trillion stars.
That's approximately right, but since the sun is not exactly the average size, the real answer is about 1/3 that, 300 billion
Just assume that the sun has the average mass of all the stars Then divide the mass of the galaxy by the mass of the sun. <span>10^30 has 30 zeroes after it. 10^42 has 42 zeroes.
The answer would have 12 zeroes which concludes a trillion stars. </span>
