Definition: In this task, you will use your knowledge about language (and common sense) to determine what element the marked number refers to. The numbers are marked with two underlines around them, like: _ number _. Your answer should be chosen from the given text, and should not contain other words.
Input: Jennifer "JJ" Jareau:  Four numbers . What is that ? 3 , something , something , 6
Penelope Garcia: That 's a unit number , 4 digits ending with a _ 6 _ . 999 possible combinations
Jennifer "JJ" Jareau: Oh , but a unit number would be registered , right ?
Penelope Garcia: Already on it , kitten
Jennifer "JJ" Jareau: Of course you are
Penelope Garcia: That 's how I roll

numbers