There is really 2 ways to go about acceleration, as it has been mentioned, it depends on the school.
Some schools put the top maths class in year 7 into a class where they did year 8 and 9 mathematics in year 8. Then they do year 10 maths during year 9 etc. This is really only done by a select school (most of which are selective) as you may gather, even the top maths class in each school would not be capable of achieving this.
For the rest of all the schools, you would have to accelerate just by yourself. There are 2 ways in which this can happen. The first is that they put you into a higher class, this is very difficult if the school doesnt know that you need to accelerate half a year in advance. This is because they would need to restructure the whole timestable for everyone for you to go into the class.
There is another way, that is to do an 'extention' course whilst in your year. This may be just learning other stuff (in the field), or you could accelerate by distance education. Distance education is where they send you stuff and you do it during your normal class.
Another, but very rare instance is to Grade accelerate. This means that you (individually) skip a whole year in all your subjects (although that rarely happens).
I am sorry to tell you this, but it is to late to accelerate. You are in year 10, so the only year you can skip is year 11. So this means you would have to go to year 12. I will asume that you only wish to accelerate in one field (mathematics). You would need to learn all the year 11 material in 10 weeks (although this is not impossible, it requires talent and LOTS of effort). Even assuming you knew the year 11 mathematics like your second hand, you would have to get into the class in term 4 this year. Timestableing does not look pritty.
So sorry, but that i what acceleration is.