Using Standard Form

Question 1:

9 \times 10^{-3} + 8.1 \times 10^{-1}

8.19 \times 10^{-1}

Question 2:

7.1 \times 10^{5} - 2.2 \times 10^{3}

7.078 \times 10^{5}

Question 3:

1.9 \times 10^{-5} \times 2.8 \times 10^{4}

5.32 \times 10^{-1}

Question 4:

\frac{9.7 \times 10^{3}}{7.9 \times 10^{5}}

1.23 \times 10^{-2}