The number 320 million written in scientific notation would be

a.320 × 106.
b.3.2 × 108.
c.3.2 × 10-8.
d.32 × 10-7.

Scientific notation is the form of expressing a very large or very small number. In this case, million means there are 6 zeros after the number. since 320 can still be simplified to 3.2 x10^2. we can add 2 to 6 to make the scientific notation equal to B.3.2 × 108. 

Bwould be the answer