I forgot to mention earlier, you might want to try the ALEKS online math curriculum (www.ALEKS.com) either at home or with the school. DS8 does ALEKS at school during his regular class' math time and in the 5th grade math class that he goes to. It is great because it checks to see what you know and then you just keep moving ahead--you can start anywhere from basic addition and subtraction to graduate level Calculus and stuff. It fills in the gaps as it goes, and when you demonstrate that you know something, it goes on. You can register at home for $20 a month, or if the school has an account or is willing to get one, it's only $40 for a whole year that way.