0.5 mm is not 5.0x10^-6 km
As for the density:
So I'm working out the volume and have 0.5mm, 10km & 100km.
I've changed 0.5mm into 5.0x10^-6 km
So it works out as 5.0x10^-6 km x 10km x 100km = 5.0x10^-4 km^3
I also need to work out mass using the desity value of 1x10^3 kg m^-3 but do I need to convert any value like I did with the 0.5mm and what would the measurement be in? kg m^-3 x km^3 becomes what?
Nope. 1 m^3 is not 0.001 km^3
1 m^3 = 1 m * 1 m * 1 m = 0.001 km * 0.001 km * 0.001 km = ....
Then you put the number in the "..." and you're right that the two m^3 will cancel out each other.
You're right. It's the "/" one
I think you can learn how to write equation here : http://www.mathhelpforum.com/math-he...-tutorial.html