I would second Aleks for filling in the holes. My DS had multitudes of gaps from basically being self taught. The nice thing is that the child takes an assessment prior to starting the course so you are pretty clear on where the holes are. The explanation have worked well for us. My son is super "mathy" and he flies through it at amazing speeds at times but since you pay by the month it doesn't matter how much gets consumed.

Shari
Mom to DS 10, DS 11, DS 13
Ability doesn't make us, Choices do!