Hi Jollymollie:
Our DD1 was really struggling with maths - as in unable to take 1 from 10 by the end of Y2. We turned to mathsfactor [http://www.themathsfactor.com/] which has worked well for us. You have choices of worksheets, the on-line tutorial with a monthly subscription or summer school [http://www.themathsfactor.com/summerschools/default.aspx]. They will test your DD's ability and start work from there.
Now I hasten to add that there are a lot of other options available out there:
Mathletics: www.mathletics.co.uk/
Mathswhizz: www.whizz.com/
and of course a range of workbooks available as well.
What we enjoy about the on-line tutorials is that it can fit around our lives and can be done as and when DD1 is able.
If your DD responds better to video games and slow, sequential building blocks of skills then I think any of these on-line options would be a good idea. I think they all have free trials and demonstrations - so do have a look around and see what you can do.
With DD1 (now Y4) I'm about to help - mainly with the writing pen on screen, which she hates, but she's doing the bulk of the work. The regular practice and clear instruction have made a huge improvement in her work. Obviously I'm speaking 2 years on from when we started - but I think it is important to understand it is a gradual thing, but the improvements do come.
Anyway I do understand - I was definitely in the same boat 2 years ago - with a very angry and unwilling 7 year old who was absolutely convinced she was no good at math. I hope one of these options may be the solution for you - but at the very least they're worth a try.