Is "Kamu berapa umur?" different from above?
"Berapa umur kamu?" literally means word-for-word
"How much your age"
umur = age
kamu = you
These two words "umur kamu" can not be separated.
They are the subject of the sentence.
They can also be shortened to "umurmu".
Berapa umur kamu?
Umur kamu berapa?
It's all the same.
Berapa - how many/much
Umur - age
Kamu - you
This is just the way we ask for someone's age, don't direct translate "How old are you?" from English to Indonesian and try to fit words into translation, because it will make you confused.
So, Indonesian, instead of using "How old are you?", we will simply use "How many is your age?" (Literal translation-wise)
Good luck learning our language