Using Standard Form

Question 1:

8.7 \times 10^{6} + 5.5 \times 10^{8}

5.587 \times 10^{8}

Question 2:

3.9 \times 10^{-6} - 9 \times 10^{-7}

3 \times 10^{-6}

Question 3:

3.8 \times 10^{-6} \times 2.5 \times 10^{-5}

9.5 \times 10^{-11}

Question 4:

\frac{4 \times 10^{-3}}{5.5 \times 10^{-3}}

7.27 \times 10^{-1}