Even Russians often do mistakes with this. I'm a native Russian and today we have studied this theme in my university. A question was: 1918. Decline it to all cases. No one has been able to answer right))) Just because in real life we rarely use it and most people do mistakes when it happens (and do not realize this).

I just try 1918 again now.
Родительный: Одной тысячи девяти ста восемнадцати
And then I check it in google:
Родительный: Одной тысячи девятисот восемнадцати

I have done the mistake now) This is very hard even for me. Further more, it seems to me that одной тысячи девятьсот восемнадцати sounds better, but it's wrong...

But I don't say that you do not need to learn it. Just bear in mind that in all cases except nominative case Russians will say this numbers wrong in 80% events.