Scientific notation has 1 number to the left of the decimal and is multiplied by 10 raised to the number of spaces the decimal is moved.
A) 5.9 x 10 ^ 9
B) 4 x 10 ^ -2
C) 1 km = 100,000 cm
4x 10^-2 x 100,000 = 4000 fireflies per km = 4 x 10 ^3 fireflies per km
5.9x 10^9 x 4x 10 ^3 = 2.4 X 10^13