Math
posted by Deborah .
5. Suppose that the volumes of four stars in the Milky Way are 2.7 × 1018 km3, 6.9 × 1012 km3, 2.2 × 1012 km3, and 4.9 × 1021 km3. What is the order of the stars from least to greatest volume?
A.) 2.7 × 1018 km3, 6.9 × 1012 km3, 4.9 × 1021 km3, 2.2 × 1012 km3
B.) 2.2 × 1012 km3, 6.9 × 1012 km3, 2.7 × 1018 km3, 4.9 × 1021 km3
C.) 2.7 × 1018 km3, 6.9 × 1012 km3, 2.2 × 1012 km3, 4.9 × 1021 km3
D.) 2.2 × 1012 km3, 4.9 × 1021 km3, 2.7 × 1018 km3, 6.9 × 1012 km3
I have no idea what the answer is. Please help.
Thank You.

exponents in this forum are indicated with the ^ symbol
So I am sure you meant
2.7x10^18 etc
The larger the exponent, the larger the number
If two numbers are have the same power of 10, then look at the factor in front to tell which is larger
e.g.
2.2x10^12 < 6.9x10^12
I am sure you can now sort them according to size 
b.

suppose that the volumes of four stars in the milky way are 2.7x10^8 km^3, 6.9x10^4 km^3, 2.2x10^12 km^3, and 4.9x10^12 km^3. what is the order of the stars from least to greatest volume?