Using Standard Form

Question 1:

3.2 \times 10^{5} + 5.8 \times 10^{7}

5.832 \times 10^{7}

Question 2:

2 \times 10^{-6} - 7.2 \times 10^{-7}

1.28 \times 10^{-6}

Question 3:

2.2 \times 10^{4} \times 2.1 \times 10^{5}

4.62 \times 10^{9}

Question 4:

\frac{4.5 \times 10^{6}}{3.2 \times 10^{-4}}

1.41 \times 10^{10}