Thinking Mathematically (6th Edition)

$5.7 \times 10^{8}$
Move the decimal point 1 place to the right to get 5.7. Then, multiply the original power of 10 by $10^{-1}$ to retain the original value. $=5.7 \times 10^{9-1} \\=5.7 \times 10^{8}$