To convert the number $40,208,000,000$ kilometers into scientific notation, follow these steps:

1. Move the decimal point in the number so that there is only one non-zero digit to the left of the decimal point. In this case, we move the decimal point 10 places to the left to get $4.0208$.

2. Count the number of places you moved the decimal point. In this case, we moved the decimal point 10 places.

3. Multiply the number by 10 raised to the power of the number of places you moved the decimal point.

Thus, the scientific notation is: $4.0208 \times 10^{10}$

Answer:

The correct answer is A:
$4.0208 \times 10^{10}$

Would you like more details on this process?

Here are 5 related questions you might explore:

1. What is the scientific notation for a smaller number, like 0.0000456?
2. How do you multiply two numbers in scientific notation?
3. What is the advantage of using scientific notation in astronomy?
4. How do you convert scientific notation back to standard form?
5. How do you perform division with numbers in scientific notation?

Tip: Scientific notation is useful for very large or very small numbers, allowing easier manipulation and clearer expression in calculations.