In a book about linguistics I've read this sentence:
Each word has up to six different such 'cases', and each case has distinct endings for singular and plural.
Now I'm pretty sure that when I studied latin for 1 year during middle school and 5 years during high school, the latin cases were always (I mean, in every declension, and more in general in every discussion) referred to as 6 in number, whether some of them have the same ending or not.
But the sentence above gives me 1% chance that I might be wrong and that you count n cases with the same ending as 1. Which also means that given a noun I might find plural and singular have different number of cases. Which pulls that 1% down to 1‰.
But why not asking?
Furthermore, I've not studied the history of the latin language, so I have no idea whether there where more cases in earlier times, which would make me think that there could have been a time where some words had, say, 6 cases, while others had 7.