Using Standard Form

Question 1:

1.2 \times 10^{-3} + 4.3 \times 10^{-4}

1.63 \times 10^{-3}

Question 2:

4.3 \times 10^{3} - 4.7 \times 10^{1}

4.253 \times 10^{3}

Question 3:

4.2 \times 10^{-4} \times 4.5 \times 10^{5}

1.89 \times 10^{2}

Question 4:

\frac{2.9 \times 10^{-4}}{2.4 \times 10^{4}}

1.21 \times 10^{-8}