My son has just completed the Carol Vorderman maths course. He loved it, and it suited me; he usually does one homework a day, not too onerous, but enough to improve his maths.
He's just finishing year 4 at school, and is working 2 years ahead of himself; he's just got a 4b in the SATS.
Now I'm stuck; I'd like to continue a similar system, it's worked for us. Any suggestions?