How Many People Are In Harry's Class?

In OoP. p.221 it’s mentioned that there’s 30 students in Harry’s class. Take a look:

“‘Cedric Diggory’s death was a tragic accident,’ said Umbridge coldly.
‘It was murder,’ said Harry. He could feel himself shaking. He had hardly spoken to anyone about this, least of all thirty eagerly listening classmates. ‘Voldemort killed him and you know it.’”

How could there be 30 students when in 5th year Gryffindor there should be no more than 10 (5 boys and 5 girls)? In fact, we don’t know for sure if there is 5 girls in Hermione’s dorm cause there’s only Hermione, Parvati and Lavender that have been mentioned. I always just assumed there were 5 students like in Harry’s dorm but Jo couldn’t be bothered to make up more characters. So if there are only 3 girls and 5 boys that would make 7 so where’s the rest come from? I can’t find anything about them having class with another house, but then I couldn’t wrestle the book off my brother for long enough to look properly (it’s MY book for goodness sake!). So if anyone has any info to clear up this mistery please post here. Then again, it might just be an editing mistake…

Well, first of all, there isn't only one house to a class. They combine houses. .. for instance, Gryffindors share Potions with Slytherins.
And secondly, I don't think that the students Rowling happens to mention often are the only people in Harry's year. I think there are many more that just may not be worth the mention.
And BTW, 3+5=8 :P

Thirty does sound like a lot.

They always combine classes. I got the impression (from Snape in the third year, when he substituted for Lupin) that it was the same combination from year to year. Potions and Care of Magical Creatures was shared with the Slytherins.

Maybe people who didn't do well last year need to repeat the class.

Starting with the assumption that they have five kids in each dorm, that would make a total of 40 kids in the entire year, and only 280 in the entire school. The books often mention Hogwarts students who don't know each other, which seems unlikley in a school of only 280. Also, at the quiddich matches they had an audience of hundreds. No, it doesn't add up.

Then again, being the only school of magic in the country, they wouldn't have such limits. I expect they would take whatever they get, with a baby-boom one year and a bust another year.

I don't think we can guess at any of the numbers.

Not only that (The only school of magic in the country...take what they get...baby-boom or bust...)

Also, I doubt that the soarting hat would be able to distribute them evenly.
It says that it puts them where they belong, not where the school has room.

It is weird. I suppose Jo just couldn´t be botherd making all those calculations. But it´s never been mentiond that they double up with another house in DADA classes. I reckon it probably is an editing mistake or lack of attention on this part. I´ve found a few mistakes like this, like the fact that the 1st september always seems to be a Sunday, as they start on a monday. I suppose I´ll just have to ignore them.

hermione1990-They have always shared with another class in DADA, so it has been mentioned.

Do they? Which house do they share with? I don't remember. If it's mentioned in the 6th book then that's no surprise. I've only read it once.

I don't exactly remember the house, but I do remember that they share a class with another house all of the time.

i swear some people are so hmm how can i put this nicely lets justsay they dont take time to think ok lets see here just cause it only shows 5 boys in harrys dorm does not mean anything there could be more boys in more rooms so mabye they only want five boys in a room so that way its not so croweded and same with classes not everyone is takeing same things i mean look at hermiony she had to use one of the time turners to get to all her classes and harry and ron didnt take most of her classes with her so i think that some kids would go to like something and then go and then anouther class would come and take a share class with someone or something but its so easy if you just think about it but most people dont reaslly try to think anymore so i dont blame you