I feel for you... I'm horrible at math and this took me absolutely forever because I'm just not mentally capable to take on Shinra.

But yes... Just save after all the wins you can and keep on trying. I ended up counting on my fingers a lot I actually just got really lucky... I even got the Sphere Grid out of this thing..somehow :O_O:

I think at www.gamefaqs.com there's a pretty good one on this mini-game that might be able to help.