# How do you write 450,000,000 in scientific notation?

450,000,000 $= 4.5 \times {10}^{8}$
You need to choose a power of $10$ such that the mantissa lies in the range $\left[1.0 , 10.0\right)$ or $\left(- 10.0 , - 1.0\right]$
450,000,000=4.5·10^8