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