Dude you should learn about computers a bit. This is something you should already know. Also Google is your friend.
K = 1,000
M = 1,000,000
G = 1,000,000,000
To convert Khs to Ghs move the decimal place to the left 6 more digits.
Exactly. This is really just stuff we all learnt at school. Even before computers a k has always been 1000
1km 1litre ect ect Just decimal system.