A parent must know what level of math and any other subject, for that matter, that their child is performing at every school year. When children enter kindergarten and the school recommends that children know their ABC's and know how to count to twenty or whatever number, it is the parent's responsibility to make sure the child is prepared prior to enrolling in school.
There are both similarities and differences between the new computerized programs and the former method of writing in math workbooks, tearing out the pages and turning them in.
The same general idea worked when it came to my son's Lego's! It was a great way to work on patterns and following directions! I would draw a pattern on paper for him to copy and recreate with his Legos. It not only helped with his color recognition, but his problem solving skills, fine motor skills and he didn't even know he was doing math!!
As children become more confident in their math skills, give them worksheets one grade level above their current grade. Help them if necessary, but when students become successful in the upper level workbooks; their confidence will really improve. The seed will be planted early and parents can watch as it grows.