Step-by-step explanation:
1000 meters is 10³ meters (just to correct the typo).
a. 100 meters = 10² meters
b. 1000000 meters = 10⁶ meters
c. 1000000000 meters = 10⁹ meters
d. 1000000000000000 meters = 10¹⁵ meters
in other words, the exponents are simply counting the numbers of zeros.