Answer:
6.41 x 10^2 km = 641 km
Explanation:
Scientific notation is a way of write numbers in two parts:
Only the figures (with the decimal point after the first digit), followed by × 10 to the power that moves the decimal point where you should be (that is, showing how many positions the decimal point moves).
On the other hand, the standard notation is the one that is normally used for not so large numbers by putting one digit behind another.
Steps:
6.41 x 10^2 km = 6.41 x 100 km = 641 km
