Hi OTGmom,
If Aleks is already availible in school, I would call the Aleks people and find out if there is a special switch the teacher should press to allow your DS to move ahead after 3 correct problems like we did at home. Also - ask them how to allow the teacher to Allow your son to take one of their assesments - perhaps at the next grade level up - to see where he is on their schema.
Switching is ok, but better to see if you can tweak what you already have, yes?

Love and More LOve,
Grinity

Coaching available, at SchoolSuccessSolutions.com