hi. I'm curious: what website or program are you using for mining bitcoin? I want to do that aswell but haven't found a viable option yet.
I have no problem reading decimals in your btc balance it means you have 0,1 dollars which is about 10 cents. well, 12 to be exact. The first decimal is always your progress towards a full dollar so when you will have 0.99999 you will be very close to getting a full dollar.
I've never found an app to read the currency in my country so I can't give feedback on how is it written. But as I see it the comma or period are there for easier understanding of how many units does a number have. like in 10.000 you have 10, and the other 3 0s means that it's in the thousand units, so ten thousands. if you would have 100000 it would have been 100.000 because you would have a hundred and then a thousand.
I haven't had my coffee yet so I hope this makes sense lol.

Hi.
Thanks a lot for your great explanations. It makes great sense to me.
My confusion was, that I didn't know about the fractions in the cents, because we only have two decimals in my currency. So thanks a lot guys...
To clear up the rest of the confusion:
You need to know if the numbers are written by the comma or the period in the currency you are reading. You need to know if, for example, the dollars and cents are separated by the comma or the period, because that is different depending on what currency you are reading.
Regarding bitcoins: I have a few things to figure out yet. As soon as I have figured out how to transfer the bitcoins to my bank account and get real money out of it, I will start a new topic about it.

@4 we do too, a fraction of a cent is not something you can obtain, its just if you have $0.0099, the next time it kicks over, you'll have $0.01 which is one cent or 1¢ to use the outmoded cent symbol.
@5 yes but the general confusion is that some countries do not use a period or dot as their decimal indicator, they instead use a comma, so 2.9 meters becomes 2,9 meters. I don't know if this means they use a dot to separate out numbers like we do, and thus 1,500.25 would become 1.500,25?

@Orko: In Denmark, we are doing it the other way than you're explaining in post 5. So we are using a comma to separate the dollars from cents, and using a period for easier reading of large numbers in groups by 3. So, regarding to numbers, we use commas like you are using periods, and periods like you're using commas.. Trust me, this can cause extreme confusion if you don't know that difference.
I would like to hear if there are other currencies with this difference...
Edit: I finally got it!
I realize that a number higher   than 9999 cents is 1 dollar. I'm not sure on why I haven't heard about this before. I've only heard things like 10 cents or 50 cents.
In danish krone, my currency, 100 øre (cents in danish) is 1 danish krone. So, in other words, this is only two decimals.
So yeah, things are quite different. It might sound weird to you, but with  this difference, it took a while for me to understand. So again, thanks a lot for your explanations and help.

I never knew that currency was like this in other countrys. That would confuse me for sure!

@slj

Using more than two decimal places isn't commonly done for US dollars and cents either, but there are a few places where it's done, such as when calculating interest. Otherwise we just round to the nearest penny ($0.01).