Quantities as an ordinary decimal number

[penza]

Express the following quantities as an ordinary decimal number:
a) The sun has a diameter of 1.392 * 10^6
I get 1392000.
b) 8.4*10^-6
I get 0.000084
Is this right

 

[jasc15]

a) yes
b) no

 

[HallsofIvy]

In b, count the decimal places again!