Quote from: jason1122 on January 16, 2016, 11:39:35 AM

Ok, thanks for the information.
So for the change a new address I being created and automatically added to my wallet?

In a sense yes. Bitcoin core 100 address pregenerated for you. The pool of pregenerated address will refill when needed. This is why you need regular backups no matter how many or few addresses you have in "receiving addresses".

Quote from: jason1122 on January 16, 2016, 11:39:35 AM

In Bitcoin QT when I show all my "receiving addresses", I can only see my one address. Not the other one where the 0.9BTC went to. I guess this is because Bitcoin QT is not fully synchronized yet?

No, change address - as CIYAM said - do not appear in that list you need to enable coin control.

To do so:

-> Settings -> Options -> Wallet -> check "Enable coin control feature" -> confirm with ok

Now to see the address, Im pretty sure core needs to sync first, but you can see it here:

-> Send -> Inputs -> check "Tree mode" -> search for your known address and click the small triangle to the left. It will open up and show the other address labeled as "(change)".