Question

Calculate 4.8×10^-3 - 9.4×10^-6. Express the answer in scientific notation rounding to 2 decimal places.

Answer 1

To perform the calculation \( 4.8 \times 10^{-3} - 9.4 \times 10^{-6} \), we first need to express both numbers with the same exponent.

1. Convert \( 4.8 \times 10^{-3} \) to have an exponent of \(-6\):
\[
4.8 \times 10^{-3} = 4.8 \times 10^{-3} \times \frac{1000}{1000} = 4800 \times 10^{-6}
\]

2. Now we can subtract the two numbers:
\[
4800 \times 10^{-6} - 9.4 \times 10^{-6} = (4800 - 9.4) \times 10^{-6} = 4790.6 \times 10^{-6}
\]

3. Convert \( 4790.6 \times 10^{-6} \) into scientific notation:
\[
4790.6 = 4.7906 \times 10^3
\]
So,
\[
4790.6 \times 10^{-6} = 4.7906 \times 10^{3} \times 10^{-6} = 4.7906 \times 10^{-3}
\]

4. Finally, round \( 4.7906 \) to two decimal places:
\[
4.79 \times 10^{-3}
\]

Therefore, the final answer is:
\[
\boxed{4.79 \times 10^{-3}}
\]