Question

To calculate \( 4.8 \times 10^{-3} - 9.4 \times 10^{-6} \), we should express both numbers with the same exponent.

The first number \( 4.8 \times 10^{-3} \) can be rewritten with an exponent of \( 10^{-6} \):

\[
4.8 \times 10^{-3} = 4.8 \times 10^{-3} \times \frac{10^3}{10^3} = 4.8 \times 1000 \times 10^{-6} = 4800 \times 10^{-6}
\]

Now we can perform the subtraction:

\[
4800 \times 10^{-6} - 9.4 \times 10^{-6} = (4800 - 9.4) \times 10^{-6} = 4790.6 \times 10^{-6}
\]

Next, we need to convert \( 4790.6 \times 10^{-6} \) into scientific notation. We can express \( 4790.6 \) as:

\[
4.7906 \times 10^3
\]

Thus, combining the exponents gives us:

\[
4.7906 \times 10^3 \times 10^{-6} = 4.7906 \times 10^{-3}
\]

Finally, we round \( 4.7906 \) to 2 decimal places:

\[
4.79 \times 10^{-3}
\]

Therefore, the final answer is:

\[
\boxed{4.79 \times 10^{-3}}
\]