The number represents the number of cards that are currently available for learning (it excludes the cards that you already have memorized, and it also will not include the cards that are sleeping at the moment).
In your case there are 6 cards currently sleeping (out of 299 cards that were learned at least once) and 187 cards are new (not yet learned one time). Additionally there are 392 cards that were completely learned (and will not be shown to be learned any more).
Answered
138 months ago by
klaus